MorphFlux
Free · No signup · Runs in browser

Free MP4 to WEBM Converter

Convert MP4 videos to WEBM for optimal web performance — open format, no upload needed.

Drop files here — any supported format

or click to browse — unsupported types are dimmed in the file picker · local processing

Max file size: images / data / documents 50 MB · audio & video 200 MB · subtitles 10 MB. This tool: up to 200 MB per file.

Why use MorphFlux?

MP4 to WEBM conversion runs entirely in your browser — open-source format for web projects, no server upload.

Open-source WEBM output

WEBM uses the VP8/VP9 codec which is completely royalty-free, making it ideal for open-source and web projects.

Runs locally in your browser

Your MP4 files are processed entirely on your device using FFmpeg WebAssembly. Nothing is uploaded to any server.

Optimized for web streaming

WEBM is designed for efficient web streaming with fast seek times and good compression for browser playback.

Free with no signup required

Convert as many MP4 files to WEBM as you need, completely free. No account, no email, no credit card required.

When would you need this?

Common scenarios where converting MP4 to WEBM is useful for web development.

1

Converting MP4 video to WEBM for use as an HTML5 video source on a website

2

Preparing MP4 files as WEBM for open-source projects tharequire license-free video formats

3

Converting MP4 to WEBM for use in web-based video editors or browser applications

About MP4 and WEBM

Understanding why WEBM is preferred for web video and HTML5 projects.

MP4

What is MP4?

MP4 (MPEG-4 Part 14) is the most widely used video format. While broadly compatible, MP4 uses H.264 which requires liing for some use cases.

WEBM

What is WEBM?

WEBM is an open-source video format developed by Google that uses VP8 or VP9 video codec. WEBM is license-free, optimized for web streaming, and supported by all modern browsers as an HTML5 video source.

Frequently Asked Questions

Everything you need to know about converting MP4 to WEBM online.

How do I convert MP4 to WEBM?

Drop your MP4 file into the converter above or click to select it. The conversion happens in your browser and you can download the WEBM when ready.

Is WEBM supported by all browsers?

WEBM is supported by all modern browsers including Chrome, Firefox, Edge, and Opera. Safari has supported WEBM since version 14.

Is my file uploaded to a server?

No. All conversion happens locally in your browser using FFmpeg WebAssembly. Your files never leave your device.

Is there a file size limit?

Files up to 200MB are supported.

How does WEBM compare to MP4 in file size?

WEBM files using VP9 codec are often similar in size or slightly smaller than equivalent H.264 MP4 files at comparable quality.

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