WebM is the default video format for Chrome screen recordings, Loom exports, and many web video downloads — but it doesn't play natively on iPhones, QuickTime, or Windows without extra codecs. This tool converts WebM to universally compatible H.264 MP4, processed entirely in your browser. No upload, no account.
Drop files here
or browse to upload
Up to 500.0 MB per file
Upload your WebM file
Drop a WebM video file. Common sources: Chrome screen recorder, Loom exports, web video downloads (YouTube, etc. in WebM format). Up to 500 MB supported.
Convert
Click Convert. FFmpeg WASM decodes the VP8/VP9/AV1 video in your WebM and re-encodes it to H.264. Opus/Vorbis audio is re-encoded to AAC.
Download the MP4
The output plays on all platforms: iPhone, iPad, Apple TV, Windows, Android, smart TVs, and every streaming service that accepts user uploads.
Share or upload
MP4 is the required format for most social media uploads (Instagram, TikTok, LinkedIn, Twitter/X all accept MP4). WebM is often rejected.
Chrome's built-in screen recording API (MediaRecorder) defaults to WebM with VP8 video and Opus audio because these are open formats with excellent browser support. Apple devices don't play VP8/VP9 natively in the system player, so QuickTime and iPhone Photos can't open WebM files without conversion.
Yes, if you have the WebM file locally. We cannot fetch videos from URLs. If you've already downloaded a WebM file using a download tool, you can convert it here. Note that downloading copyrighted content may violate terms of service — only convert content you have the right to use.
The audio is re-encoded to AAC at 128 kbps. MP4 containers don't natively support Opus or Vorbis (in broad compatibility mode), so re-encoding is necessary. AAC at 128 kbps is high quality and plays everywhere.
Both are video container formats. WebM uses VP8, VP9, or AV1 video codecs (open-source, royalty-free) with Vorbis or Opus audio. MP4 typically uses H.264 (AVC) or H.265 (HEVC) video with AAC audio. H.264 MP4 has broader hardware decoder support — especially on mobile devices and smart TVs.
Yes. Loom exports and Microsoft Teams recordings in WebM format convert cleanly to MP4. The resulting file is ready to upload to video platforms, share via email, or edit in Final Cut Pro, Premiere, or DaVinci Resolve (all of which support H.264 MP4 natively).
Something not working? Report a bug
