Resize video
Downscale 4K to 1080p, 1080p to 720p, or pick a custom size. Aspect ratio preserved.
drop a video here
or click to choose
About resizing
Resizing always means re-encoding the video. We use H.264 (libx264) at the quality level you pick, with width auto-computed from the target height so the aspect ratio doesn't change.
For most uses, downscaling (large → small) preserves quality well; upscaling (small → large) just makes a blurry file bigger. There's no AI super-resolution here.
FAQ
Does the file get uploaded anywhere?
No. Open this page, turn off your wifi, then try a file — it still works. That's the test.
What's the maximum file size?
Browser memory is the limit. WebAssembly caps at 2–4 GB per file. Most laptops handle 1080p videos under a gigabyte comfortably.
Why is it slow on my phone?
FFmpeg-WASM runs on your CPU, not hardware video encoders. Phones have less CPU, so encoding takes longer.
Can I cancel mid-encode?
Yes. The Cancel button terminates the worker immediately. You'll wait a few seconds the next time you start.