Turn your MKV file into an MP4 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.
MP4 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 MP4, or keep editing the file in REQO.
MKV (Matroska) is an open container that can hold any codec plus unlimited audio tracks, subtitle tracks and chapters. That flexibility makes it great for archives and useless for sharing.
The practical problem: Browsers, phones and social uploads reject MKV almost universally. Editing tools often refuse to import it, or import picture without audio. Nobody can preview it without installing VLC first.
MP4 solves that. Plays natively on every phone, browser, TV and editing app with no extra codecs. Every upload form accepts it, from YouTube and LinkedIn to Slack and email. H.264 keeps files small enough to send while still looking sharp at 1080p.
MKV can hold several audio tracks and a stack of subtitle tracks, and MP4 handles that far less gracefully. The conversion keeps the picture and the primary audio track, which is what you want for sharing or uploading. If your MKV is a multi-language archive you care about keeping intact, keep the original as well as the MP4.
| MKV | MP4 | |
|---|---|---|
| Container | Matroska | MPEG-4 Part 14 |
| Typical codecs | Almost anything: H.264, HEVC, AV1, VP9 | H.264 video, AAC audio |
| Best for | Archiving with multiple audio and subtitle tracks | Sharing anywhere, uploads, web embeds |
| Plays on | VLC and desktop players; rarely anywhere else | Every phone, browser, TV and editor |
| File size | Depends entirely on the codec inside | Small for the 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 MP4 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 MKV 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.
Soft subtitle tracks are not carried into the MP4. If you need captions on the output, run the file through REQO’s transcription and burn styled captions into the video instead.
To WebM
Turn your MKV file into a WebM that plays where you need it, right in your browser.
OpenTo MOV
Turn your MKV file into a MOV that plays where you need it, right in your browser.
OpenTo GIF
Turn your MKV file into a GIF that plays where you need it, right in your browser.
OpenTo MP4
Turn your MOV file into an MP4 that plays where you need it, right in your browser.
OpenTo MP4
Turn your WebM file into an MP4 that plays where you need it, right in your browser.
OpenTo MP4
Turn your AVI file into an MP4 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.