PRIVATE BROWSER PROCESSING
Resize video without stretching the picture
Choose the maximum width you need and keep the original aspect ratio. Useful before uploading, embedding, sending to a phone, or keeping a lightweight copy of a larger source.
Video resizer
Resolution should match where the video will actually be seen
The resizer preserves aspect ratio and calculates the matching height automatically. Upscaling a small source does not create real detail, so choose a width at or below the original whenever possible.
Privacy and limitations
Processing uses FFmpeg WebAssembly locally. The video is not uploaded by this tool. Closing or refreshing the page clears the working file. Speed depends on the browser, device memory, source codec, duration, and resolution, and tools that re-encode are not lossless.
Common questions
Which video formats are supported?
The FFmpeg core handles common formats such as MP4, MOV, WebM, MKV, AVI, MPEG, M4V, 3GP, TS and WMV, though the browser may not preview every format.
Is my video uploaded to DJAI?
No. The source file is read and processed in your browser on your device.
Why can the first run take longer?
The browser downloads an FFmpeg WebAssembly core of roughly 31 MB the first time processing is needed; caching can help later runs.
BUILD WITH DJAI
Want to build a tool like this one?
This tool runs entirely in the browser. Explore DJAI Academy’s practical building courses.