How to use the MP4 to WEBM converter
- Choose your MP4 video or drop it on the box.
- Check the settings. "Same as original" resolution is fastest. Lower it to 720p for a smaller file.
- Click "Convert to WEBM". A progress meter shows how far along it is.
- Download your WEBM.
Why convert MP4 to WEBM?
WebM is royalty-free and plays natively in browsers, which makes it a good choice for website background videos and HTML5 players.
- MP4: usually lossy, so quality drops a little each time it is re-encoded.
- WEBM: royalty-free.
- WEBM: small files with VP9.
The browser encoder uses VP8 for speed. Keep web videos short and at 720p for the smallest, fastest-loading files.
MP4 vs WEBM
| MP4 | WEBM | |
|---|---|---|
| Full name | MPEG-4 Part 14 | WebM |
| Type | Video | Video |
| Created by | Moving Picture Experts Group (MPEG) (2001) | Google (2010) |
| Compression | Lossy | Lossy |
| Typical codecs | H.264 + AAC | VP9 or VP8 (sometimes AV1) + Opus or Vorbis |
| Best for | Sharing videos online, phone recordings, social media uploads and streaming | Web video, browser screen recordings and HTML5 players |
| Plays on | Windows, macOS, iPhone, Android, smart TVs, game consoles and every modern browser | Chrome, Firefox, Edge, Android and VLC; support in older iPhones, PowerPoint and many editors is limited |
Does converting MP4 to WEBM lose quality?
MP4 (H.264) has to be re-encoded to WEBM (VP9 or VP8 (sometimes AV1)). At "Balanced" quality the difference is very hard to see; choose "High" for footage you will edit again.
How long does it take?
Re-encoding video uses your device's processor. A short clip takes seconds; a 10-minute 1080p video can take several minutes. Choosing 720p makes it 2–3 times faster.
What is an MP4 file?
MP4 is a container that usually holds H.264 or H.265 video with AAC sound. It is built on Apple's QuickTime file structure and became an ISO standard in 2001. Because almost every phone, browser, TV and editing app can play it, MP4 is the safest choice when you need a video to just work.
What is a WEBM file?
WebM is an open, royalty-free video format made by Google for the web. It is based on Matroska and uses VP8, VP9 or AV1 video with Opus or Vorbis audio. Browsers play it natively, and many screen recorders and download tools produce WebM files.
Frequently asked questions
Do I have to pay or sign up to use the MP4 to WEBM converter?
No. There is no account, no payment and no watermark. The only limit is 1 GB per file, set by what browsers can handle.
Is my file uploaded to a server?
No. The converter runs inside your browser using WebAssembly, so your file is processed on your own device and never sent to us or anyone else.
Will the WEBM sound and look as good as the MP4?
MP4 (H.264) has to be re-encoded to WEBM (VP9 or VP8 (sometimes AV1)). At "Balanced" quality the difference is very hard to see; choose "High" for footage you will edit again.
Can I convert WEBM back to MP4?
Yes, use the WEBM to MP4 converter.
An MP4 plays without sound. What should I do?
The audio may use a codec your player does not support (for example AC3). Convert it to MP4 again so the sound becomes AAC.
Can I use it on my phone?
Yes. Open the page in your phone's browser and choose a file. Phones have less memory than computers, so very large files are better converted on a laptop or desktop.