Free tool
Free MP4 to WebM converter, no upload
Convert MP4 to WebM in your browser.
Your video
Drag a file here, paste it, or choose one.
.mp4, .mov, .m4v, .mkv, .webm, .avi, .wmv, .flv, .3gp, .gif. Up to 500 MB.
Up to 10 minutes long.
Your video never leaves your browser. The conversion runs on this machine.
More options
WebM encodes more slowly than MP4 here. Keep the tab open the whole way, and trim long clips first.
Result
Worked example
Measured on our own 17 second H.264 MP4 at 1280 by 720, converted to WebM at Balanced.
Source MP4
3.0 MB
WebM, VP8 and Vorbis
1.1 MB
It took 14 to 20 seconds over two runs, and the size moved by a few percent, because VP8 in real time mode adapts to how busy the machine is. The source MP4 was exported at a generous bitrate, which is why the WebM came out smaller.
1. Add the MP4. 2. Pick the quality. 3. Encode locally. 4. Download the WebM.
What Interlace does
A video for your site, made from the page copy.
- Paste the copy from the page
- Interlace makes a short narrated video in your brand
- 16:9 for the page, 9:16 and 1:1 for social
Real Interlace output, unedited. Shown silent and sped up.
Your file
homepage-hero.mp4
For a video tag on the site
Questions
Asked and answered
No. The file is opened by the page and converted by ffmpeg compiled to WebAssembly, on your own machine. There is no upload step, and closing the tab discards everything.
VP9 makes smaller files, but the VP9 encoder in the WebAssembly build of ffmpeg this page runs on crashes on ordinary video, so we write VP8, the codec WebM launched with. Every browser that plays WebM plays VP8. If the smallest file is the goal, an MP4 with H.264 usually beats VP8.
Chrome, Firefox and Edge play WebM, and so does Safari on a recent Mac. For older iPhones and some smart TVs, keep the MP4 as a second source in your video tag.
On your own site, serve both: list the WebM first and the MP4 second in the video tag, and each browser picks the one it can play. For email, slides and an LMS, MP4 is still the safer file.
Yes, re-encoded to Vorbis at a bitrate set by the quality, or one you pick under More options. Choose Remove for a silent background video.
500 MB and 10 minutes. Everything runs inside one browser tab, which has a fixed memory budget, and the encoder runs on a single thread. A rewrap takes seconds; a full re-encode runs at about real time for 720p and several times the clip length for 1080p. For anything bigger, a desktop encoder such as HandBrake is the better tool.
Turn this into a video
Create an account and start from a document, script, or prompt.