WebM with VP9 typically produces smaller files than an H.264 MP4 at the same quality, and it is open and royalty-free. Web developers use it for hero videos, background loops and product demos. Convert your MP4s here in a few clicks.
How to convert MP4 to WebM (VP9)
- Drop your MP4 files in the box above, or click to pick them. You can add as many as you like.
- WebM (VP9) is already selected as the output format. Switch on other formats if you want them too.
- Optional: open Advanced Settings to resize by percentage, width or height, and add more sizes.
- Click Start Conversion, then download each file or all of them at once. Nothing is uploaded: the conversion runs in your browser.
Why convert MP4 to WebM (VP9)?
Serving WebM with an MP4 fallback is the classic recipe for fast, compatible web video.
Frequently asked questions
Is WebM smaller than MP4?
Usually yes. VP9 compresses more efficiently than H.264, so the WebM is often noticeably smaller at similar quality.
Is there a watermark or size limit?
No watermark and no server-side limit. The only limit is your device memory, since the conversion runs locally.
Are my videos uploaded?
No. The video is decoded and encoded in your browser, on your device. Nothing is sent to a server, which also means there is no file size limit other than your device memory.