Convert Video
Change a video's format without uploading it — the encoder is downloaded to you instead.
What it does
Convert Video works on MP4, MOV, WEBM, MKV and AVI with ffmpeg and audio engines compiled for the browser, so the recording or video is processed by your own computer or phone — the same programs a desktop editor uses, without installing one.
When you need it
Usually right before sending or publishing: a video too heavy for WhatsApp, a voice note full of hum, a clip that needs captions because the feed plays it muted, an interview to turn into text.
Limits and caveats
Long or high-resolution files take as long as your device needs, and a phone is slower than a laptop. The engines download once, the first time, and come from KIVO itself. The original file is never changed: you always download a new one. Everything happens in your browser, so the file never leaves your device.
How to convert video
- Drop the video. Nothing is uploaded.
- Pick a format and a quality.
- Wait — encoding in a browser is slower than a desktop app — and download.
Everything happens on this device: no file is uploaded and nothing leaves the browser.
Frequently asked questions
- Why is there a 32 MB download the first time?
- That is ffmpeg, compiled to WebAssembly. Every other free converter runs it on their server, which means your video goes there. This runs it on your machine, and the cost of that is fetching the encoder once. It is cached afterwards.
- Why is it slower than my desktop app?
- Because a browser tab cannot use your machine the way a native binary can — no hardware encoder, one thread. For a clip it is a fair trade for not uploading anything. For a two-hour recording it is not, and a desktop tool is the right answer.
- How big a file can it handle?
- Everything happens in memory, so the practical ceiling is a few hundred megabytes before the tab runs out. If it fails on a large file, trim it first.
- Do my files get uploaded?
- No. This tool runs entirely in your browser, so the file never leaves your device.