Convertor

Video converter

MP4 to WebM

Convert an MP4 video to lightweight WebM for the web — smaller files, browser-native.

Runs in your browser
MP4WEBM100% local · no upload

Drop your mp4 here, or browse

Up to 500 MB · .mp4

Runs 100% in your browser — your file is never uploaded.

Guide

How to convert mp4 to webm

  1. Pick your MP4 file

    Select an .mp4 video up to 500 MB.

  2. Convert to WebM

    Your browser encodes VP9 video into a lightweight WebM container.

  3. Download the WebM

    Use the smaller file on the web.

TipRequires Chrome or Edge — VP9 encoding is not available in Firefox or Safari.

Format details

Input formats
MP4
Output format
WEBM
Privacy
No upload · processed locally

Frequently asked questions

Why use WebM?

WebM with VP9 gives excellent quality per byte, ideal for web pages, previews and embedding.

Why does my browser not support this?

VP9 encoding uses the browser’s VideoEncoder, which only Chromium-based browsers (Chrome, Edge) expose. Safari and Firefox will show the unsupported message.

Is the file smaller than MP4?

Usually yes for the same quality, because VP9 compresses more efficiently than H.264.

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