About Convert Video Format
Convert Video Format — free, private, browser-based video tool
Convert a video to MP4 or WebM (MOV and MKV with Pro) in your browser. Pick a quality level and download — nothing is uploaded.
Why use Convert Video Format
- ·Files stay on your device — nothing is uploaded
- ·No signup needed
- ·Works in any modern browser, on any OS
- ·Free daily use; Pro removes limits and watermarks
How to use it
- 1Drop the video.
- 2Choose the output format — MP4 plays everywhere — and a quality: High, Good (default), Medium or Low.
- 3Press Convert & Download and wait for the progress bar.
Codecs and quality
MP4, MOV and MKV are encoded as H.264 with AAC audio; WebM as VP9 with Opus audio. Quality levels map to x264 CRF 18, 23, 28 and 32 — lower means better quality and a larger file. MP4 output is written with fast-start so it begins playing before it fully downloads.
Common conversions
MOV to MP4 for iPhone videos that will not play on Windows or Android; MKV to MP4 for OBS recordings and TV playback; WebM to MP4 for screen recordings headed to editors or social sites; MP4 to WebM when a web page or tool asks for WebM.
How it works
Hybrid renderer: WebGL2 for color grading and effects, WebCodecs for decode/encode, ffmpeg.wasm for muxing and exotic codecs. Multi-threaded via SharedArrayBuffer where COOP/COEP is available. The processing code runs inside the page, so your file is not uploaded to a server — you can confirm this in your browser's DevTools → Network tab.