Convert WebM to MP4 Free
Convert WebM to MP4 and turn a WebM file into a web-ready MP4 that plays on any device. This free WebM converter to MP4 adds no account, no watermark, and no monthly cap, drop your WebM and get a widely compatible MP4 back in seconds. Need to convert WebM format to MP4 in your browser? That is exactly what this does.
Files up to 2GB · Output: MP4 (H.264, AAC)
Uploading
Converting
Finalizing
Processing for 0:00...
Still working. Larger files take longer. You can leave this tab open and come back.
Click to upload or drag & drop
WebM · MP4 · MOV · MKV · Up to 2GB
No sign up needed. Just drop your video.
Processing time depends on file size and your upload speed.
Advertisement
No account required
Just upload and go. Nothing to sign up for, no email, no credit card.
No watermark, ever
Your MP4 comes back clean. No branding added.
Files deleted in about 90 minutes
Your video does not live on our servers. Privacy by default.
How It Works
Upload your WebM
A WebM file up to 2GB. Drag and drop or click to browse. MP4, MOV, and MKV are accepted too.
VidClean converts it to MP4
WebM stores video with VP8 or VP9, which an MP4 container cannot hold, so the video is re-encoded to H.264. The result is a widely compatible MP4, not a lossless copy.
Download the MP4
Ready in seconds and plays on any device, browser, or editor. If the MP4 is larger than you need, compress the video to shrink it before uploading.
Who uses this
Anyone with a WebM file that will not play in a video editor, on a phone, or on a platform that expects MP4. Screen recorders, browser-based capture tools, and OBS often export WebM, and many apps simply cannot open it. Converting to a widely compatible MP4 makes the clip work everywhere. If you only need the audio track, extract audio from the file instead.
Drop your WebM, get an MP4 back. No editor required.
Why a WebM has to be re-encoded, not re-wrapped
WebM is a deliberately narrow subset of Matroska that Google built for the open web, and the whole point of it is that it only ever carries royalty-free codecs. That means VP8, VP9 or AV1 for the picture and Opus or Vorbis for the sound. MP4 supports none of those in any form that real players will decode. There is no way to lift the streams out of a WebM and drop them into an MP4 untouched, so both the video and the audio genuinely have to be decoded and encoded again.
This is the one real difference between converting WebM and converting a MOV or an MKV. Those two often already hold H.264, so the job can be close to a re-wrap. A WebM never does. It also explains where your files come from: any browser that recorded video used the MediaRecorder API, and MediaRecorder writes WebM. Browser-based screen recorders, in-page camera capture, web meeting recordings, video saved from streaming sites, OBS when its output is set to WebM, Discord and Google Meet exports are all WebM for that reason.
What comes back is H.264 video with AAC audio at 128 kbps, wrapped in an MP4 with faststart so playback can begin before the download finishes. Resolution and frame rate are left alone. One consequence worth knowing in advance: VP9 and AV1 are more efficient codecs than H.264, so an H.264 file holding the same picture at the same visual quality can end up larger than the WebM it came from. Nothing was added to your video. That is simply what older, more widely supported compression costs.
What people convert WebM to MP4 for
Browser and screen recordings
Anything captured by a recorder that runs inside a browser tab lands as WebM, because that is the only thing the browser recording API produces. Course platforms, ticketing systems and clients almost always want MP4 back, so this is the most common reason people arrive here.
Meeting recordings
Google Meet and several web conferencing tools hand you a WebM. Converting it to MP4 means you can drop the recording into a shared drive, a knowledge base or a video editor without anyone needing a special player.
Video saved from the web
Streaming sites frequently serve VP9 in a WebM container because it is efficient and free to use. Once the file is on your disk, MP4 is the version that will actually open in your phone gallery, your editor and your TV.
Uploading to social platforms
Several platforms accept WebM on paper and then fail on it, or transcode it badly. Uploading an H.264 MP4 gives you a predictable result rather than a coin flip, and it is what their own recommended export settings ask for.
Dropping clips into a video editor
Timeline editors handle H.264 MP4 far better than VP9 WebM, which many of them either refuse outright or scrub through slowly. Converting first is usually faster than fighting the import. From there you can trim the video or merge several clips.
Sending to someone on an older device
WebM support is good in modern browsers and patchy everywhere else. Older phones, older TVs, in-car screens and a lot of desktop software have never supported it. H.264 MP4 is the format with the longest reach of anything in common use.
WebM to MP4: codecs, size and what does not survive
| Inside the WebM | Can MP4 hold it? | What you get |
|---|---|---|
| VP8 video | No | Re-encoded to H.264 |
| VP9 video | No | Re-encoded to H.264 |
| AV1 video | Not in any playable way | Re-encoded to H.264 |
| Opus audio | No | Re-encoded to AAC, 128 kbps |
| Vorbis audio | No | Re-encoded to AAC, 128 kbps |
| VP9 alpha channel | H.264 has no alpha | Flattened, transparency is lost |
- Input formats
- WebM, and also MP4, MOV and MKV. The output is always MP4. VP8, VP9 and AV1 video are all accepted, as are Opus and Vorbis audio.
- File size
- Up to 2GB per file free, up to 5GB with Pro. No monthly cap and no limit on the number of files. WebM is efficient, so 2GB of it is a lot of video.
- Video output
- H.264, encoded to a constant quality target rather than a fixed bitrate, so detailed footage receives more bits than a static screen recording of the same length.
- Audio output
- AAC at 128 kbps, converted from whichever of Opus or Vorbis the WebM carried. Opus is a strong codec at low bitrates, so a very low bitrate Opus track re-encoded to AAC is the one case where you might notice a difference on close listening.
- Resolution and frame rate
- Preserved exactly. Nothing is scaled or frame-rate converted. A 1440p 60fps WebM comes back as a 1440p 60fps MP4.
- Why the MP4 can be larger
- VP9 typically needs meaningfully fewer bits than H.264 for the same perceived quality, and AV1 needs fewer still. Converting to H.264 therefore sometimes produces a bigger file. If size matters more to you than compatibility, run the result through Compress Video.
- Transparency
- Not preserved. VP9 in WebM can carry an alpha channel, which is why the format shows up in animated stickers and overlay assets. H.264 in an MP4 has no alpha channel at all, so any transparency is flattened during conversion. If you need the transparency, keep the WebM.
- Privacy
- No account is needed. Your WebM and the MP4 it produced are both deleted from the servers about 90 minutes after the job finishes.
Frequently Asked Questions
Everything you need to know about converting WebM to MP4.
Will the quality change when I convert WebM to MP4? expand_more
WebM stores video with VP8 or VP9, which an MP4 container cannot hold, so the file is re-encoded to H.264. This is not a lossless copy, but VidClean uses a quality-targeted encoder so the result is a widely compatible MP4 that looks clean on typical content like talking heads, screen recordings, and tutorials.
What formats can I upload, and what do I get back? expand_more
You can upload WebM, MP4, MOV, or MKV. The output is always an MP4 (H.264 video, AAC audio) for broad compatibility across phones, browsers, editors, and social platforms.
How large can my WebM file be? expand_more
Files up to 2GB are supported. That covers long screen recordings and high-resolution clips without forcing you to split the file first.
Is my file kept private? expand_more
Yes. Files are processed on a private server and automatically deleted about 90 minutes after the job finishes. We never view, share, or store your content.
Is it free, or is there a paid plan? expand_more
Completely free. No account, no signup, and no watermark. There is no monthly cap and files up to 2GB are accepted.
How long does the conversion take? expand_more
Roughly real-time on the input duration. A one-minute clip typically finishes in under a minute. A five-minute clip takes a few minutes. Larger files and higher resolutions take proportionally longer.
Why can I not just rename a .webm file to .mp4? expand_more
Because the extension is only a label. The file still contains VP8, VP9 or AV1 video and Opus or Vorbis audio, and an MP4 player has no way to decode any of those. Renaming produces a file that either refuses to open or opens to a black screen. The streams have to be decoded and re-encoded into codecs MP4 actually supports, which is what this tool does.
Where do WebM files even come from? expand_more
Almost always from a browser. The MediaRecorder API that web pages use to capture video writes WebM, so browser-based screen recorders, in-page camera capture, web meeting tools and Google Meet recordings all produce it. The other common source is video saved from streaming sites, which frequently serve VP9 in WebM because it is efficient and carries no licensing cost.
My MP4 came out larger than the WebM. Is that normal? expand_more
Yes, and it is expected rather than a fault. VP9 needs roughly a third fewer bits than H.264 for the same perceived quality, and AV1 is better still. When the same picture is re-encoded into the older, more universally supported codec, the file can grow. You are trading size for the ability to play on more or less anything. If the size matters, compress the MP4 afterwards.
Does the conversion keep transparency from a VP9 WebM? expand_more
No, and no MP4 converter can. VP9 in a WebM container supports an alpha channel, which is why transparent stickers and overlay clips are distributed that way. H.264 inside MP4 has no alpha channel in the specification, so the transparency is flattened during conversion and previously transparent areas are filled in. If you need to keep the transparency, keep the WebM.
Will an AV1 WebM convert? expand_more
Yes. AV1 is decoded like any other input and re-encoded to H.264. AV1 is a heavier codec to decode than VP9, so an AV1 file can take somewhat longer to process than a VP9 file of the same length and resolution, but the result is the same widely compatible MP4.
Also try: Compress Video at vidclean.net/compress-video
Last updated: July 2026