Drop in an MP4 and get a WEBM back.
Same picture, a noticeably smaller file, and it plays in every current browser. No account, no watermark.
By ShinobiTools Team · Last updated: September 2026
Every converter here is free, full size, no account. Photos convert in your browser and never leave it, except camera RAW files and SVG tracing. Those, like video, audio and e-books, need our server — and we delete them right after.
How to convert MP4 to WEBM: drop the MP4 in, check that WEBM is what you convert to in the menu, and download the result once the encode finishes. Everything happens on our server, so there's no MP4 to WEBM converter to install and nothing to download first. VP9 is slow to encode, so each MP4 convert to WEBM takes longer than other conversions here; a WEBM convert back to MP4 finishes quicker.
The WEBM here uses VP9, a newer codec than the H.264 inside most MP4 files. Newer codecs find more ways to describe the same picture with fewer bits — typically 25 to 40 percent smaller for the same visual quality on real footage. VP8, the older WEBM codec, is slightly more compatible but makes bigger files, so this tool uses VP9. The trade is time: VP9 encoding is slower than making an MP4. In practice it works as a way to compress MP4 for the web and change the format in one go.
Need a WEBM format converter to MP4 instead? The same box works in reverse: drop a WEBM and pick MP4 in the menu. That's also how to convert a WEBM file to MP4 on a phone: open this page in the phone's browser, pick the file, and the MP4 download lands like any other. MOV and MKV are in the menu too.
If you've used CloudConvert MP4 to WEBM or CloudConvert WEBM to MP4 before: same idea, different limits. This one needs no account and has no daily cap; files can be up to 1200 MB and 20 minutes long, and when it's busy, free conversions wait their turn.
Use it for video you host yourself: a background clip, a product demo, anything with a <video> tag on your own page. Every current browser plays WEBM, and the smaller file means it starts sooner.
Do not use it for a file you are sending to a person. Older desktop players, some phones and plenty of editing programs will not open it, and then you have made a smaller file that nobody can watch. Send those an MP4.
WEBM can store transparency (an alpha channel), but an MP4 never contains any: H.264 has no alpha channel. So converting a normal MP4 gives a WEBM with the same solid background, not a transparent one. If you need a WEBM transparent background, the background has to be cut out first with a video background remover; converting alone can't do it.
The audio track carries over as Opus at 128 kbps, so a clip with sound keeps it. Video larger than 1080p (4K, for example) comes back at 1080p, which keeps the file small enough for a web page.
Safari has played VP9 in WEBM since version 14 (2020), so on any Mac or iPhone kept reasonably up to date it works. If your audience includes people on much older hardware, the safe pattern is two source files in the video tag — WEBM first, MP4 as the fallback — and the browser picks.
This runs on our own machine, not in your browser. Your file is deleted the moment the result is ready. Limits: 1200 MB and 20 minutes per upload on the free tier.
Need to shrink the file to a target size instead of just the format? Compress video does that. Want an exact resolution too? Resize video handles that.
Smaller at the same quality, but supported in fewer places. WEBM for video on your own website, MP4 for anything you send to a person.
Typically 25 to 40 percent on real footage. Animation and screen recordings often do better than that.
Yes, since Safari 14 in 2020. For much older devices, list a WEBM and an MP4 as two sources in the video tag and let the browser choose.
VP9 does more work per frame to get the file smaller. That is the trade you are making.
Yes: drop the WEBM in the box above and pick MP4, or use the convert video format page, which has MP4 as the default. To free convert WEBM to MP4 is the same free converter, no account and no watermark, and it is quicker than the other direction, since MP4 encodes faster than WEBM. It works one clip at a time, either way, and also converts to MOV or MKV.
At the same file size, WEBM (VP9) usually looks a little better than MP4 (H.264), because the codec is newer; at the same quality, WEBM is the smaller file. Converting re-encodes the video, which always loses a tiny amount, but at standard settings it is not visible in normal viewing.
Not really — upload an MP4 for those. WEBM is for serving video in a web page's video tag, where it streams efficiently in Chrome and Firefox.
Yes: an MP4 to WEBM converter free of accounts, watermarks and daily caps, the same as the MP4 converter free in the other direction. Every free convert costs only the extra time VP9 encoding takes.
Streaming video inside a webpage's video element. WEBM was designed for the web — smaller file, same quality, and licence-free for developers to use.
Only if the source has one, and an MP4 never does. A clip with no background behind the subject needs WEBM alpha, and that transparency has to exist before converting: remove the background with a video background remover first.
VP9. An MP4 to WEBM VP8 conversion would give a bigger file for the same quality, so VP8 isn't offered.
The file is uploaded, converted and deleted right after; every MP4 to WEBM online conversion here works that way, and nothing is kept.
Often: an MP4 to WebM conversion to VP9 usually makes the file smaller, so it works as an MP4 to WebM compressor too. MP4 to WebM transparent background isn't possible here, since an MP4 has no transparency to carry over. As a file converter it takes MOV and MKV too.
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