Audio·Video tool
Change video aspect ratio
Changing the video aspect ratio to vertical or square, cutting the original frame, or placing it within the margins.
Processing result
Share result
Share the tool link and result text together. No URL is included in the result. Check the below content and then share it.
Run video aspect ratio change in the browser
640×360 when selecting 9:16 in the vertical video, it creates a vertical frame. Center cropping removes the left and right areas, while full display compresses the entire video to fill the remaining space with dark margins. Since the screen does not move along the subject, check the result and then save it.
Re‑encode with a new video
Does not upload selected file to the server. Saved in a new container and codec, so input format, quality, and file size may vary. Compare the estimated size with the original and verify directly by playing the result
Cutting removes the outer region based on the center of the screen. Full view reduces the original and adds dark padding. No movable subject tracking or auto reorganization is performed.
Limitations on files and devices
Up to 100MB·Works on 60-second videos. Detects the storage format supported by the browser and outputs as MP4 or WebM. Keep the tab open during encoding. Some files may not be processed due to device memory and codec support.
Frequently Asked Questions
Does changing the screen ratio automatically adjust the position of people or objects?
No auto tracking is performed. Center cutting cuts the video based on the center of the frame, while full view preserves the original and adds padding.
Does the screen get cut when converting vertical to video?
When ‘Show all’ is selected, the entire scene is displayed with the remaining area filled with dark padding. When ‘Fill screen’ is selected, the edges that do not match the ratio are cut off from the center.
Where is my video processed?
The video is encoded as a new frame in the browser without being uploaded to the server. The video quality and processing time may vary depending on device performance and the storage format supported by the browser.
Calculation criteria and reference materials
- MDN — MediaRecorder
Re-encoding the capture stream using the browser’s supported container and codec. The supported format and output quality depend on the browser.
- MDN — Canvas captureStream
Draw the current video frame onto the local Canvas and capture it as a video stream for browser recording.
- WebKit — MediaRecorder API
Describes Canvas·Web Audio stream recording and format detection in WebKit implementation. Current device codec support is detected during execution.
Verification of calculation criteria: · Calculation·verification principles · Report errors