Convert WEBM to MP4 online
Convert a WEBM video to MP4, the format most widely supported by players and social platforms, processed entirely in your browser.
or click to select it
Convert a WEBM video (common in screen recordings and web downloads) to MP4, the format with the widest compatibility across players, phones and social platforms, without installing anything or uploading the file to a server.
Re-encodes both the video and audio of a WEBM file into the MP4 container using H.264 (video) and AAC (audio), the most widely compatible combination available today.
Use cases
- Convert a WEBM screen recording before editing it in software that only accepts MP4.
- Share a video downloaded from the web with someone whose device can't play WEBM.
- Upload a video to a platform that specifically requires MP4.
How it works
- 1
Upload your WEBM video
Drop the file in or select it from your device.
- 2
Click Convert
ffmpeg.wasm re-encodes the video to MP4 (H.264 + AAC) in your browser.
- 3
Download the MP4
Once it's done, download the converted video.
Technical details
Uses ffmpeg.wasm inside a Web Worker in your browser. Since it re-encodes the entire video (not just the container), it can take several minutes depending on file size and your device's power.
Frequently asked questions
Why does this take longer than other conversions?
Re-encoding video requires re-processing every frame, which is far more CPU-intensive than, say, extracting just the audio.
Does it keep the quality?
It uses a balanced quality setting, very close to the original to the eye.