Everyday Tools
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Calculate·convert·text tools: 200 free versions without installation.

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200 free tools

200 tools

StudyTextCalculation·mathematicsUnit conversionDate·timeDevelopment·designDraws·generationLiving ExpensesAudio·VideoPhoto · imagePDF·documentFile·compression
01 / Study

Online Lecture Playback Speed Calculator

Add up online lecture durations and calculate watch time and time saved at 1.25×, 1.5×, and 2× speed. Calculate up to 300 lectures for free.

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02 / Study

Course Completion Planner

Calculate how much to study each day to finish your remaining online lectures by the deadline. Build a daily plan that accounts for playback speed, study days, note-taking, and review.

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03 / Text

Count characters

Number of characters including and excluding spaces, UTF-8 bytes, and word and line count can be checked directly. The entered text is not saved or sent.

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04 / Math and calculations

Percentage calculator

Calculate the amount and ratio value after applying a certain percentage from the total value.

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05 / Math and calculations

Percentage change calculator

Compare the previous and next values to check the change and increase/decrease rate.

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06 / Math and calculations

Percentage difference calculator

Calculates relative differences based on the average of two positive measurements.

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07 / Math and calculations

Simplified ratio calculator

Simplify the ratio of two integers by their greatest common divisor and calculate the composition ratio.

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08 / Math and calculations

Proportion calculator

A:B = C:X calculates the unknown X in the proportional equation.

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09 / Math and calculations

Average calculator

Calculates the count, total, and arithmetic average of a number list.

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10 / Calculation·Mathematics

Weighted average calculator

Enter the value and the weight corresponding to its importance to calculate a weighted average.

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11 / Math·Calculations

Median and mode calculator

Aligns items to check the median, mode, minimum, and maximum.

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12 / Math·Calculations

Standard deviation calculator

Calculates the population and standard deviation of numerical data.

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13 / Math and Calculations

Greatest common divisor·Least common multiple calculator

Calculate the greatest common divisor and multiple criteria for multiple positive whole numbers.

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14 / Math and Calculations

Fraction calculator

Convert the results of two fraction operations into rational fractions.

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15 / Math and Calculations

Quadratic Equation Calculator

Find the discriminant and real or complex conjugate roots of ax²+bx+c=0.

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16 / Math and Calculations

Triangle area calculator

Verify whether a triangle can be formed, its perimeter, and its area using the lengths of all three sides.

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17 / math

Circle Area and Circumference Calculator

Calculate the diameter·circumference·area of a sphere using radius.

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18 / math

Rectangle calculator

Calculates area, perimeter, and diagonal in horizontal and vertical dimensions.

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19 / math

Trapezoid Area Calculator

Calculates the trapezoid area using parallel sides and height.

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20 / Calculation·Mathematics

Cylinder volume calculator

Calculate the volume and outer area of a cylinder using radius and height.

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21 / Calculations·Mathematics

Cone Volume Calculator

Calculates the volume, surface area, and outer surface of a cone.

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22 / Calculations·Mathematics

Volume·surface area calculator

Enter the radius to calculate the volume and surface area of a sphere.

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23 / Calculations·Mathematics

Pythagorean Calculator

Calculate the altitude between two right angles of a right triangle.

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24 / Calculations·Mathematics

Arithmetic Sequence Calculator

Calculate the last term and the sum using the first term, common difference, and number of terms.

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25 / Calculations·Mathematics

Geometric Sequence Calculator

Calculate the last term and the total sum using the first term, common ratio, and number of terms.

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26 / Calculations·Mathematics

PermutationCombination Calculator

Calculates the permutations and combinations of selecting r out of n different items.

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27 / Calculations·Mathematics

Prime Factorization Calculator

Break down a positive integer into decimal parts.

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28 / Calculations·Mathematics

Rounding, Ceiling, and Floor Calculator

Comparing three rounding methods based on selected decimal places

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29 / Unit Conversion

Length unit converter

Convert the length value to a different unit and compare the results for each unit.

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30 / Unit conversion.

Width unit converter

Change the width value to a different unit and compare results for each unit.

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31 / Unit conversion.

Volume unit converter

Converts volume value to different units and compares results for each unit.

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32 / Unit conversion.

Weight unit converter

Converts weight values to different units and compares the results for each unit.

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33 / Unit conversion.

Speed unit converter.

Convert speed values to different units and compare results for each unit.

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34 / Unit conversion.

Data size unit converter

Convert data size values to different units and compare results for each unit.

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35 / Unit conversion.

Pressure unit converter

Convert pressure values to different units and compare results for each unit.

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36 / Unit conversion.

Energy unit converter

Convert the energy value to other units and compare results by unit

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37 / Unit conversion.

Power Unit Converter

Converts the rate value to different units and compares results by unit.

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38 / Unit conversion.

Angle unit converter.

Converts angle values to different units and compares results for each unit.

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39 / Unit conversion.

Frequency unit converter

Convert frequency values to different units and compare results for each unit.

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40 / Unit conversion.

Time Unit Converter

Convert time values from one unit to another and compare results for each unit.

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41 / Unit conversion.

Temperature converter

Convert Celsius·Fahrenheit·Kelvin temperatures into each other

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42 / Unit conversion.

Fuel consumption unit converter

Convert fuel consumption units from km/L, L/100km, and US mpg.

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43 / Unit conversion.

PX·REM converter

Convert pixels and rem values according to the standard font size.

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44 / Date and time.

Date Difference and Countdown Calculator

Calculate the number of days between two dates, including the start and end dates.

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45 / Date and time

Date plus·minus

Find the date N days before or after the specified date.

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46 / date and time

Number of workdays calculator

Count the number of days from Monday to Friday within the period and exclude holidays entered manually.

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47 / date and time

Weekday Counter

Check how many times each weekday is included from Monday to Sunday during the period.

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48 / date and time

Annual days calculator

Checks which day of the year the selected date is and the remaining days.

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49 / date and time

ISO Week Number Calculator

ISO Based on 8601, it finds parking days and Mondays and Sundays of the corresponding month.

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50 / date and time

Unix timestamp converter

Convert seconds or milliseconds timestamps to UTC date and device local time.

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51 / date and time

Time Summation Calculator

Add the durations of multiple tasks to calculate total time, minutes, and seconds.

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52 / date and time

Time Difference Calculator

Calculates time between start and end time and handles after midnight.

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53 / date and time

Running pace calculator

Calculate fuel consumption and average speed per km using distance and total time.

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54 / text

English uppercase/lowercase conversion

Swaps uppercase, lowercase, and first letter of words in English letters.

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55 / text

Trim Leading and Trailing Spaces

Remove unnecessary spaces before and after each line and organize indentation differences.

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56 / text

Remove empty lines

Remove empty lines and lines with only spaces.

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57 / text

Remove Duplicate Lines

Keep only the first occurrence of the same line and remove duplicates.

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58 / text

Text line sorting

Sorts the line list in alphabetical or numeric order.

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59 / text

Reverse line order

Reverses the order of the list from the last line to the first line.

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60 / text

Add line number

Specify the start number and separator to assign numbers to each line.

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61 / text

Add Text to Leading and Trailing Lines

Adds fixed characters at the beginning and end of each line.

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62 / text

Batch replace text

Specify a search string to replace all matching parts with a new string.

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63 / text

Extract lines containing strings

Select only lines that contain or do not contain a specific string.

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64 / text

Count occurrences of duplicate lines

Counts how many times each line appears and displays them in descending order.

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65 / text

Splitter·line‑splitting conversion

Convert comma lists to line lists or connect with another separator.

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66 / text

Unicode normalization

Normalize combining characters and compatible characters in NFC, NFD, NFKC, and NFKD formats.

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67 / text

Fullwidth and Halfwidth Alphanumeric Converter

Convert halfwidth halfwide ASCII characters and spaces into the opposite form.

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68 / text

Create URL slug

Organize titles into readable paths using lowercase and hyphens.

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69 / text

Word frequency analysis

Count the occurrences of lines divided by spaces

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70 / text

Text line comparison

Compare the same line positions in two texts to find the changed line.

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71 / text

Insert line break

Adds line breaks to groups of characters specified in a long line.

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72 / text

Text length truncation

Only the specified number of characters remain; ellipsis is added

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73 / text

Remove Hidden Space Characters

Remove embedded spaces, BOM, and soft hyphens from the copied text.

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74 / text

Reading time calculator

Calculate expected time based on the number of characters and reading speed per minute.

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75 / text

Extract initial consonants from Hangul

Extract the first consonant of a completed Hangul syllable.

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76 / development·design

JSON sort·verifier

JSON check syntax and clean up indentation or compression format

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77 / development·design

JSON→CSV converter

Convert an object array into a CSV table with column names.

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78 / development·design

CSV→JSON converter

Use the first row header as a key to convert it into a CSV JSON array.

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79 / development·design

Base64 encoding·decoding

Converts UTF-8 text to standard Base64 or restores it to original form.

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80 / development·design

URL encoding and decoding

Encode or restore special characters in URL components in percent format.

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81 / development·design

HTML special character conversion

Converts five special characters in HTML into or restores as entities.

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82 / development·design

Unicode escape conversion

Convert or restore a string to UTF-16 \uXXXX format.

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83 / development·design

Text·hexadecimal conversion

Represents text in UTF-8 bytes as hexadecimal or converts it back to text.

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84 / development·design

Number Base Converter

Converts an integer to a binary representation 2·8·10·16.

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85 / development·design

HEX·RGB·HSL converter

Convert 6-digit HEX colors to RGB and HSL.

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86 / development·design

Color contrast checker

Check the WCAG compliance and AA·AAA text standards for the two HEX colors.

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87 / development·design

CSS gradient generator

Create a CSS linear gradient code using two colors and angles.

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88 / development & design

CSS shadow generator

Generates box-shadow code using horizontal/vertical movement, opacity, and spread values.

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89 / development & design

Screen ratio size calculator

Calculates a new height while maintaining the original width and height ratio.

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90 / development & design

Screen PPI Calculator

Calculates pixel density of the screen using pixel resolution and screen diagonal inch.

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91 / development & design

Responsive CSS clamp generator

Generates dynamic font size CSS based on the text width of two screens.

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92 / development & design

Query string parser

Decodes key and value in URL query, and identifies duplicate keys as an array.

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93 / development & design

URL structure analyzer

破 down the web address into protocol·host·port·path·query·hash.

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94 / random selection & generation

UUID generator.

Generates the required number of random UUID v4 identifiers.

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95 / random selection & generation

Password generator

Generates a random password containing English letters, numbers, and symbols.

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96 / random selection & generation

Random number drawing

Randomly select whole numbers within the range without duplicates.

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97 / random selection & generation

Random shuffle of list

Mix participants or tasks in random order.

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98 / random selection & generation

Random team division

After mixing the roster, divide the teams so that the number of members differs by less than 1.

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99 / random selection & generation

Dice rolling

Roll multiple dice to get the desired number of faces and then check the sum.

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100 / Drawing·Generation

Coin flip

Flip coins multiple times to count front and back results and counts.

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169 / living·costs

Compound interest calculator

Calculate the expected balance and annual balance using the initial amount, monthly deposits, and assumed annual return.

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170 / living·costs

Savings Goal Calculator

Calculates the monthly savings amount needed to reach the target amount and timeline, then checks if it can be contributed to meet the goal.

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171 / living·costs

Break-even point calculator.

Fixed cost per period · selling price per unit · variable cost calculates break-even sales volume and revenue at that time.

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172 / living·costs

Sales Margin Calculator

Calculates profit and target margin selling price per item based on product cost, selling price, fee rate, and shipping cost.

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173 / living·costs

VAT calculator

Calculate VAT and the total from the purchase price or the amount including VAT of multiple transactions.

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174 / living·costs

Travel Exchange Rate Budget Calculator

Calculates the expected foreign currency amount based on the original budget, directly entered exchange rate, and discount rate.

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175 / living·costs

Installment vs. one-time payment comparison calculator

Compare the expected total amount and monthly payment range with the payment amount, installment months, annual fee rate, and one-time payment discount rate.

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176 / development·design

IPv4 subnet calculator

Check network, mask, address range, and host count using IPv4 address and CIDR prefix.

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193 / living·costs

Loan repayment calculator

Compare monthly payments for equal principal and interest · equal principal and interest based on loan principal, input interest rate, and duration.

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194 / living·costs

Deposit/Savings Interest Calculator

Calculates the pre‑tax interest and expected amount at maturity for a lump sum savings account, monthly deposit, input interest rate, tax rate.

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195 / living·costs

Korean Weekly Paid Rest Allowance Calculator

Estimate South Korea’s weekly paid holiday allowance from average scheduled work hours over 4 weeks, hourly wage, attendance on scheduled workdays, and a comparable worker’s scheduled workdays over 4 weeks.

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196 / living·costs

Baking pan size conversion

Adjust ingredient ratios based on the existing pan shape and new pan bottom area. Supports round, square, and rectangular pans.

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198 / living·costs

Shoe size comparison

Compare the Nike·Crocs official chart’s US·EU and brand local labeling for adult female foot length.

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213 / Living·Expenses

Take-Home Pay Calculator

Enter salary or annual salary, tax-exempt wage and number of family members to calculate the expected monthly net amount for 2026.

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214 / Living·Expenses

Retirement Pay Calculator

Estimate Korean statutory severance pay before tax from your start date, separation date, and wages before separation.

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201 / Audio·Video

Animated GIF Maker

MP4·Select a short segment from the WebM video and create a GIF that moves. 5 seconds·50 frames or less, adjust size and playback speed, and save it in the browser.

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206 / Audio·Videos

Video trimming

MP4·WebM·MOV. Select start and end times and save a maximum 30-second segment. Video and sound are re-encoded in browser, and the result file is checked before downloading.

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207 / Audio·Videos

Reduce video size

Re-encode the video at different resolutions and quality below 60 seconds and compare the sizes. Process the file in the browser, check the actual result, and save it.

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208 / Audio·Videos

Remove audio from video

Create a copy of the video without the audio track. Instead of lowering the volume, save a new video with only the image in the browser.

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209 / Audio·Videos

Change video aspect ratio

Convert a horizontal video to vertical and square. Cut off the center or create a new video with the full screen within the margin and save it in a browser.

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210 / Audio·Videos

Video audio extraction

MP4·WebM·MOV. Play audio in browser and save it as a separate file. Only videos up to 60 seconds are processed; the actual storage format is displayed based on browser codec support.

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211 / Audio·Videos

Audio Trimmer and Merger

Cut sections from up to 3 audio files, combine them in order, and add a short fade. Check the waveform and time, then save as WAV PCM 16-bit.

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212 / Audio·Videos

Audio format conversion

MP3·M4A·WAV and other supported audio formats, convert them. PCM WAV storage uses MP3·WAV input, compressed storage uses the current device’s supported format.

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202 / Photos·Images

Remove photo background

Remove the background of the person portrait photo from the browser and save as transparent PNG. The first run is for public examples; your photo is processed on the device.

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203 / Photos·Images

Image upscale · sharpening

Zoom the small image 2x with AI in the browser and save it as a PNG. A 3·4x output uses additional interpolation, and the image will not be sent outside the device.

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204 / Photos·Images

Photo text extractor

Read Hangul·English in photos in the browser and copy·save as text. Supports JPG·PNG·WEBP; does not send photos and text to the server.

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167 / audio·video

Convert subtitle file

Convert SRT·VTT·SMI subtitles to SRT or VTT. Check Korean encoding and multilingual class, then save as UTF-8 file.

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168 / audio·video

Adjust subtitle sync.

Move subtitles forward or backward or correct slowly drifting sync. Check negative timing and overlap, then save as SRT or VTT.

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164 / study

Wordbook·Flashcard

Create a pair of flashcards for front and back and evaluate directly or enter answers. Only practice mistakes from this session and save as CSV or JSON.

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165 / study

Korean and English typing practice

Check time, accuracy, and errors in Korean and English sentences. Measure completed characters and save results distinguishing mobile/PC keyboards.

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166 / study

Create seat arrangement table.

Set empty seats and fixed seats in the seat grid, and arrange names. Save the actual row/column layout as PNG·SVG·CSV.

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161 / Study

Target Grade Calculator

Use the received score and reflection ratio to calculate the remaining average needed for the target final score. Separate impossible targets from completed assessments.

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162 / Study

Textbook·problem study quantity plan

Divide the page and problem and completed page count by the remaining study days. Check the number by date and unassigned amount, then save it as CSV or calendar.

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163 / study

Create a review schedule

Create a calendar using the learning date and directly set review intervals. Reflect rest days and save to CSV or ICS calendar file.

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160 / Lifestyle and Costs

Group Expense Split Calculator

Divide the costs for multiple payers and participants by category. Consider equal, proportionate, or direct amounts, refunds, and already sent amounts to calculate the remaining payment.

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158 / PDF·Document

Add PDF annotations and text

Add Korean text, rectangles, and highlights to a PDF. Check the applied page and position, and save a copy while preserving the original.

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159 / PDF·Document

Add PDF watermark

Add text or logo watermarks to multiple PDF pages. Adjust position, angle, and opacity, then verify the actual result and save a copy.

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157 / PDF·Document

Add PDF signature

Place a handwritten or signature image on a PDF page. Check the position·size and save a new PDF copy with the original content.

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186 / PDF·document

Fill Out a PDF Form

Fill in the PDF text field, checkboxes, and selection list, then save as a copy. Supports Korean input, and the file is processed in the browser.

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101 / PDF·Document

Merge PDFs

Rearrange and merge a PDF file into one. Up to 20–200 pages can be processed in the browser and a copy is saved.

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102 / Photos·Images

Reduce photo size

JPG·PNG·WEBP compress photos to match target KB. Compare original and result, then save as JPG or ZIP

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103 / Development·Design

Create QR code

Create a QR code for address, text, Wi-Fi, and contact info, then save as PNG or SVG. The input is processed by the browser.

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104 / Study

Grade calculator

Calculate your GPA from course grades and credits on a 4.5, 4.3, or 4.0 scale. Exclude P/F credits and include previous grades in your cumulative GPA.

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105 / Photos·Images

Image size adjustment

Adjust photos individually by pixels or ratio. Choose the width-to-height ratio and exact size, then save in preview.

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106 / Photos·Images

Image format conversion

JPG·PNG·WEBP convert to desired format. Convert multiple photos at once, then save with transparency and actual file format

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107 / PDF·Documents

PDF split·extract

Divide the PDF into pages or sections, or extract only the needed pages. Process in the browser and save as PDF or ZIP.

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108 / PDF·Documents

Organize PDF pages

Swap page order·delete·rotate by viewing PDF thumbnail. Save a copy with the original preserved.

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109 / Photos·Images

Cut·rotate photo

Select the area to cut above the photo and rotate·flip horizontally or vertically. Save a edited copy via touch or number entry.

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110 / Photos·Images

Merge photos

Merge multiple photos into vertical, horizontal, or grid formats. Adjust order, spacing, and background, then save as a single image.

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111 / Photos·Images

Add watermark to photo

Add text or logo to the photo. Check location, size, and opacity, then save multiple photos with the same settings.

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112 / Photos·Images

Photo mosaic — Hide

Cover or mosaic the selected area of the photo with black. Save a copy of the PNG with the covered area.

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113 / PDF·Documents

Convert the image to PDF

Organize photos by order·paper·margins and create a single PDF. Process it in the browser and save a preview before creating a new copy.

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114 / PDF·Documents

Convert PDF to Images

Save the pages needed for the PDF as PNG·JPG. Choose the page and resolution, then download each image or a ZIP file.

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115 / PDF·Documents

Add PDF page numbers

Set the start number and position of the PDF, then add page numbers. Specify pages excluding the cover, and save a new copy.

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116 / PDF·Documents

PDF text extraction

Extract text from a PDF as per-page text. Copy the result or save as TXT. Does not include OCR for scanned photos.

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205 / PDF·Documents

Reduce PDF size

Compare structure optimization to preserve text, links, and formats in PDFs with image compression for quality. Check the final size and first page, then save it in your browser.

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117 / Files·Compression

Compress ZIP file

Combine multiple files into a single ZIP file. Choose the compression method and ZIP name, then save a copy with the original content.

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118 / Files·Compression

Unzip compressed file

Check the file list inside the ZIP and download only the required files. Unzip in a browser. RAR·7z·ZIP encryption is not supported.

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119 / Files·Compression

File hash verification

Calculate the SHA-256·SHA-512 checksum of the file and compare with the expected value. You can split large files into smaller parts, read them, and cancel processing mid-process.

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120 / Files·Compression

Batch change file names

Attach consecutive numbers or replace names to multiple files. Preview the modified names and save a ZIP copy.

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121 / Development·Design

Regular expression test

Check JavaScript regular expression matching, capture groups, and substitution. Stop for slow patterns and process input in the browser.

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122 / Development·Design

JWT content verification

JWT check header, payload, expiration, and issuance time. No tokens are stored or transmitted; signature verification is not performed.

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123 / Development·Design

JSON structure comparison

Compare JSON additions, deletions, and changes without ignoring object key order and spaces. Also check differences in array positions and large numbers.

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124 / Development·Design

Creates UTM link.

Enter source, medium, and campaign to create a tracking link. Verify the replacement UTM content and copy the completed URL

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125 / Development·Design

YAML·JSON conversion

Convert YAML to JSON bidirectionally. Preserve large numbers and check types, aliases, and annotations that cannot be converted to JSON.

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126 / Development·Design

SQL Formatter

Sort SQL according to PostgreSQL·MySQL dialects. Adjust indentation and keyword case, but no query is executed.

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127 / Development·Design

Markdown preview

Check the Markdown document on the screen and save as HTML or MD. No user HTML is executed, and external images are not loaded.

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128 / Development·Design

Create a Markdown table

Paste tables from Excel or spreadsheets and edit cells. Select column alignment and copy or save the Markdown table.

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129 / Life·Costs

Unit price comparison

Compare product unit prices based on the number of bundles, volume, and shipping fee. Calculated in g·kg, mL·L, and count units.

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130 / Lifestyle and Costs

Calculate coupon and duplicate discount

Compare the order, limit, minimum purchase, and free shipping conditions of precision and fixed-amount coupons. Also check the input order, reverse order, and unused coupon amounts.

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131 / Lifestyle and Costs

Travel Fuel Cost Calculation

Compare travel costs per vehicle using distance, fuel consumption, and directly entered fuel prices. Also calculate round-trip distance, total tolls, parking fees, and estimated costs per person.

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132 / Lifestyle and Costs

Actual fuel efficiency calculation

Calculate actual fuel consumption by the distance of the full refueled segment and the consumed fuel. Combine multiple segments to check km/L and L/100km together.

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133 / Lifestyle and Costs

Recipe quantity adjustment

Adjust multiple ingredient amounts according to portion and multiple. Enter fractions like 1/2 and copy or save the result with the original unit.

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134 / Lifestyle and Costs

Pizza Size·Price Comparison

Compare pizza orders by diameter, number of slices, and price. Mix different sizes and account for shipping costs to determine total area and price per area.

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135 / Lifestyle and Costs

Appliance power usage calculation

Summarize kWh and household costs of multiple appliances and home expenses using consumption power·time·days. It reflects operating efficiency and standby power and differs from actual progressive rates.

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136 / Lifestyle and Costs

Subscription Cost Calculator

Compare monthly and annual subscription fees based on the same criteria. Check the monthly adjustment amount, the sum of payments for 12 future months, and the manually entered renewal schedule.

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137 / Study

Pomodoro timer

Set focus·short break·long break and record sessions. Provides pause·focus screen and CSV save. The next phase is started directly

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138 / Study

Online timer

Run up to 5 timers together. Provides preset options for 1·5·10·25 minutes, individual time stops, optional stop sounds, and recording saving.

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139 / Study

Stopwatch

Record elapsed time, lab sections, and cumulative time per lab. Save up to 200 labs as CSV, excluding pause times.

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140 / Lifestyle and Costs

Korean Full Age Calculator

Age from date of birth to reference date, next birthday, and elapsed days. Multiple birthdays and leap years for February 29 are calculated together.

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141 / Development and Design

Read QR code in a photo

Read and copy QR content from screenshots or photos, or save as TXT. Read address and Wi-Fi information in the browser without automatic execution.

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142 / Development and Design

Create barcode

Generate CODE128·EAN-13·EAN-8·UPC-A barcodes and save as PNG·SVG. Check the check numbers and prepare the image for printing.

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143 / Photos and Images

Image color extraction

Extract the HEX·RGB color of the representative color in photos and save the palette. Click the photo or enter the original coordinates to check the color of specific pixels.

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144 / Photos and Images

Create favicon

Convert photos into PNG·ICO icons by size. Select trimming options for margins, background, and center, then save the manifest and installation tags.

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145 / Math and Calculations

Linear equation calculator

Solve the linear system of equations with coefficient and right side. Check for no solution, unique solution, free variable, and row elimination steps.

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146 / Math and Calculations

Matrix calculator

Calculate matrix addition, subtraction, multiplication, transposition, determinant, inverse matrix, and RREF. Check the row elimination process and numerical tolerance.

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147 / Math and Calculations

Regression and correlation calculator

Use x, y data to check regression line·Pearson correlation coefficient·R² and residual. Plot points and predicted values, then save as CSV·SVG.

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148 / Math and Calculations

Binomial Probability Calculator

Calculate exact, less than, greater than, and interval probabilities using execution frequency and success probability. Save an exponential distribution graph and a total probability table.

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149 / Date and Time

Find world time and meeting time

Compare the date with the local time in the city. Find the common available time for the next 72 hours and save the result as text.

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150 / Date and Time

Create a calendar schedule file

Create an ICS file for the daily, time‑specified, repeating schedule. Verify the actual occurrence date and time zone, then import it directly into the calendar.

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151 / Date and Time

Create a print calendar

Choose a month and start day to create a calendar with notes. Save as PNG·SVG or print on A4 width.

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152 / Date and Time

Create a weekly schedule

Edit time blocks by day to create a weekly schedule. Check overlapping times and save as PNG·SVG·print.

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155 / Photos and Images

Create meme·text image

Add text above and below the image and save as PNG·JPG. Supports Hangul line breaks and placement inside/outside the image.

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156 / Photos and Images

Document photo scanning correction

Adjust the four corners of photos to straighten the document. Supports automatic selection for bright paper and saving multiple PNG·PDF files.

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154 / Photos and Images

Create transparent signature

Draw a signature with a finger·pen·mouse and save it as a transparent background PNG.

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153 / Photos and Images

Check and delete photo EXIF data

Check the location and shooting info of the photo and create a copy of the PNG without metadata. Re‑check the output file while preserving the original.

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192 / development·design

Cron Expression Generator

Executed every minute·every hour·every day·every day·every month as a Unix 5-field cron job. The following execution example is checked using the device’s time zone.

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199 / math

Draw function graph

Compare sin·cos·tan and polynomials on the same screen. Set the x·y range and angle units, check coordinates with the slider, then save as SVG.

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200 / Calculation·Mathematics

Scientific Calculator

Calculate brackets, powers, factorials, trigonometric functions, and log formulas directly. Provides circle and radians modes and current tab calculation history.

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197 / development·design

View·edit CSV table editor

Open CSV·TSV files as a table to search·edit and save. Guides formatting content for UTF-8·EUC-KR and delimiters.

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