Turn your MP4 file into a WebM that plays where you need it, right in your browser.
Drag and drop the file, or click to browse. Files up to 500 MB are supported, and nothing is installed.
WebM is already selected, so there is nothing to configure. You can switch formats in the panel if you need to.
We convert on our servers, usually in under a minute. Create a free account to download the WebM, or keep editing the file in REQO.
MP4 is the closest thing video has to a universal format: an MPEG-4 container that almost always holds H.264 video and AAC audio, which every browser, phone, TV and social platform can play without a plugin.
The practical problem: MP4 is already the safest format, so the usual reason to convert away from it is a specific destination that wants something else.
WebM solves that. Streams natively in Chrome, Firefox and Edge with no plugin. VP9 delivers smaller files than H.264 at the same visual quality, which cuts bandwidth on a busy page.
Convert to WebM when the file is destined for a web page rather than a person. VP9 typically delivers the same picture in noticeably less data than H.264, which shows up directly in page-load times on a video-heavy site. For anything a human will download or upload elsewhere, stay with MP4.
| MP4 | WebM | |
|---|---|---|
| Container | MPEG-4 Part 14 | WebM (Matroska-based) |
| Typical codecs | H.264 video, AAC audio | VP8 / VP9 / AV1 video, Opus audio |
| Best for | Sharing anywhere, uploads, web embeds | Web embeds and browser recordings |
| Plays on | Every phone, browser, TV and editor | Chrome, Firefox and Edge; hit and miss elsewhere |
| File size | Small for the quality | Very small at the same quality |
Yes. Convert and preview the result for free, then create a free account to download it. There is no per-file charge and no watermark on the WebM itself beyond the free-plan badge.
No. The conversion runs on our servers and the whole flow happens in your browser, so it works the same on Windows, macOS, Linux, iPhone and Android.
Converting re-encodes the video, so it is not bit-for-bit identical. We encode at a high quality target, which keeps the result visually indistinguishable from the MP4 on normal viewing. Converting the same file back and forth repeatedly will eventually show, so keep your original.
Up to 500 MB per file. For anything bigger, trim or compress it first, both are free tools here.
Your upload is processed and then held only as long as your project needs it. Nothing is published, indexed or shared unless you create a share link yourself.
To MOV
Turn your MP4 file into a MOV that plays where you need it, right in your browser.
OpenTo GIF
Turn your MP4 file into a GIF that plays where you need it, right in your browser.
OpenTo MP3
Pull the audio out of your MP4 file and save it as MP3, right in your browser.
OpenTo WebM
Turn your MOV file into a WebM that plays where you need it, right in your browser.
OpenTo WebM
Turn your AVI file into a WebM that plays where you need it, right in your browser.
OpenTo WebM
Turn your MKV file into a WebM that plays where you need it, right in your browser.
OpenFree, in your browser, and the file stays open in a full video editor afterwards.