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.
Which resolution to choose
Downscaling is one of the most effective ways to make a video smaller, because the number of pixels falls with the square of the dimension: 4K to 1080p is a quarter of the pixels, and typically a fraction of the file size for the same visual quality at normal viewing distances.
- 1080p — the safe default. Sharp on a phone or a laptop, and universally supported.
- 720p — noticeably smaller files, still perfectly watchable on a phone. Good when you are fighting an upload limit.
- 480p / 360p — for when size matters more than looks, such as a long screen recording that only has to be legible.
- 1440p / 4K — only worth keeping if the footage was shot that way and will be watched on a large screen.
Upscaling — picking a size larger than the source — will not add detail. It makes the file bigger and, usually, softer.
Aspect ratio
The height you pick sets the width automatically so the picture is never stretched. If you need a different shape rather than a different size — square for a feed, or vertical for a phone-first platform — that is a crop, and cropping means deciding what leaves the frame. The editor is the place for that.
If the goal is a specific file size rather than a specific resolution, compress targets a size directly and picks the bitrate for you. For the common 4K case there is a dedicated 4K to 1080p page.
FAQ
Does the file get uploaded anywhere?
No. Nothing is uploaded. Open your browser's network tab while you convert and you will see your file never leaves the page. Once the converter itself has downloaded, it keeps working on this device even with no connection.
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.