Convert WebM to MP4
Convert Google's WebM videos to universal MP4 format. Free, in your browser, no file uploads.
.webm · up to 100 MB
Why convert WebM to MP4
From Google's web format to the universal standard
Universal compatibility
From WebM to MP4: works in Safari, iOS, smart TVs, editing software, and any social network.
Guaranteed privacy
Your video never leaves your device. Local conversion with FFmpeg.wasm, no server uploads.
Equivalent quality
VP9 and H.264 have comparable efficiency. The re-encoding difference is practically imperceptible.
Perfect for recordings
Chrome records screen in WebM. Convert in seconds to edit or share on any platform.
How it works
Three steps, no hassle
Select your WebM file
Drag or select your .webm file — a screen recording, Chrome video, or web download. No registration required.
Local H.264 re-encoding
FFmpeg.wasm re-encodes the VP8/VP9 video to H.264 and audio to AAC on your own device. No uploads.
Download your MP4
The resulting MP4 works in any player, social network, or editing software. Ready to use.
FAQ
Got questions?
WebM is an open-source video format developed by Google in 2010, based on the Matroska container. It uses the VP8 or VP9 video codecs (also from Google) and Vorbis or Opus audio. It was designed to be the royalty-free video standard for the web, as an alternative to the patented H.264. YouTube, Chrome, and Firefox adopted it widely.
Although Chrome and Firefox play WebM natively, many other environments don't support it: Windows Media Player, iOS/iPhone devices, most smart TVs, video editing software (Premiere Pro, Final Cut), and platforms like Instagram or TikTok that require MP4 for uploading content. MP4 is the most universally compatible format.
Conversion involves re-encoding from VP9 to H.264, which entails some technical loss. However, VP9 and H.264 have comparable compression efficiency, and at CRF 23 the visual difference is practically imperceptible. For general video content, the perceived quality of the result is identical to the original.
Chrome and many web tools (Loom, Screencastify, the browser MediaRecorder API) record the screen in WebM format by default. If you need that video for a presentation, to edit it in Premiere/DaVinci, or upload it to Instagram, you need to convert it to MP4. This is the most common reason users seek this conversion.
WebM with VP9 is very efficient in compression, comparable to H.264. The resulting MP4 may be slightly larger (5-15%) since H.264 tends to be somewhat less efficient than VP9 for the same level of visual quality. For screen recordings, the difference is usually minimal.
WebM is natively supported by modern Chrome, Firefox, and Edge, but not by Safari on iOS/macOS without extensions. MP4 with H.264 is supported by all browsers without exception, including Safari, as well as all operating systems and devices. MP4 is the only truly universal format.
WebM to MP4: WebM history (Google 2010, based on Matroska), VP8/VP9 codecs, royalty-free video formats, and screen recording workflows
WebM was announced by Google in May 2010 at Google I/O, as part of its initiative to create a completely royalty-free video ecosystem for the web. The format is based on the Matroska (MKV) container and uses the VP8 video codec, also acquired by Google along with the company On2 Technologies in 2010 for $124 million. The stated goal was to compete directly with H.264, whose patents were managed by the MPEG LA consortium and could generate significant licensing costs for large-scale video distributors.
WebM adoption was uneven. Mozilla Firefox and Google Chrome adopted it from the beginning; Apple Safari and Microsoft Internet Explorer initially rejected it, forcing web developers to maintain both MP4 and WebM versions of every video. YouTube adopted VP9 (VP8's successor) in 2014 as its main streaming format to reduce bandwidth, and today serves most of its content in WebM/VP9 or the newer AV1. However, for maximum device compatibility, MP4/H.264 remains the standard download format.
The most common use case for WebM-to-MP4 conversion today is screen recordings. The browsers' MediaRecorder API, integrated into Chrome since 2016, records video in WebM format by default. Popular tools like Loom, Screencastify, and Chrome DevTools native recording produce WebM files. When these videos need to be edited in Adobe Premiere Pro, Final Cut Pro, or DaVinci Resolve — or uploaded to Instagram, TikTok, or LinkedIn — they must be converted to MP4. This everyday friction is the main reason why the search 'webm to mp4' exceeds 500,000 monthly global queries.