shycut

Convert MP4 to WebM for the web

WebM is the open format browsers stream natively. Drop an MP4 here to get a WebM for your site, or for a web app that asks for one.

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Drop your video here

Choose your video

MP4, MOV, WebM or MKV. It opens right here, on your device.

  • Nothing uploaded
  • No sign-up
  • No watermark

Tested in the browser

BrowserResultWhat came out
Google Chrome 155ConvertedWebM: VP9 video, Opus sound, 1280×720
WebKit 27.2 (Safari’s engine)ConvertedWebM: VP9 video, Opus sound, 1280×720

On October 24, 2026, a 10-second 1280×720 MP4 (H.264 video, AAC sound) went through this page’s button in each browser, and what came out was read back with ffprobe.

The test file carried a location tag; no converted copy kept it.

When to turn MP4 into WebM

If you host video yourself, offering WebM next to MP4 lets browsers pick the open format, and VP9 usually gets the same picture from fewer bits than H.264.

Keep the MP4 too: older iPhones and many desktop apps still prefer it, so a page usually lists the WebM first and the MP4 as the fallback.

MP4 and WebM, in short

MP4
The format that plays almost everywhere: phones, browsers, TVs, editing apps and every social platform take it. Inside is usually H.264 video and AAC sound.
WebM
Google’s open web format, with VP8, VP9 or AV1 video and Opus or Vorbis sound. Browser screen recorders and many downloaded web videos come as WebM.

How to convert

  1. Open the MP4

    Press the button and drop the file, or pick it from your files. It opens in this browser tab: nothing is uploaded, so there is no upload limit to hit.

  2. WebM is already chosen

    The save window opens set to it. Change the file name or the quality if you like.

  3. Save

    The new file is written on your device and downloaded. Several files? Drop them together and they are converted one after another.

What changes, what stays

Picture and length
Nothing is cut or reframed: the video keeps its own picture size and runs from start to end.
Sound
The first sound track, at its own level, in stereo at most.
Quality
Small, Balanced or High; Balanced is chosen to begin with.
Details about you
The file is written from scratch, so none of the original’s metadata comes along: no location, no camera or phone model.

Questions

Does it write VP9 or VP8?

VP9 where the browser can encode it, then VP8 or AV1 if it can’t. The test table shows what came out in each browser.

Will the WebM be smaller than the MP4?

Usually, at the same quality setting, since VP9 is the more efficient codec. Pick Small to go further.

How do I put both on a website?

Use a video tag with two sources, the WebM first and the MP4 second, so every browser finds one it plays.

Your video stays with you.

Open Shycut, drop the video in and export. Free, with no account, and your video never leaves your device.

Choose your video

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