WebM to MP4 Converter

Convert WebM files to MP4 format instantly. Fast, free, and secure online video converter.

Upload WebM Video

Drag & drop or click to upload

Supports .webm files

Result Preview

Converted MP4 video will appear here

Convert WebM Videos to MP4 — No Upload Required

WebM is ideal for streaming but often fails to play on iPhones, in video editing software, or when uploaded to social media platforms. This converter uses FFmpeg WebAssembly to transform your WebM file into the universally compatible MP4 format right inside your browser. Your video never leaves your device, and there are no file size limits imposed by a server.

WebM → MP4 via browser FFmpeg

Why Use This Tool?

Fixes iPhone playback issues

iOS does not support WebM. Converting to MP4 lets you play browser recordings and downloaded web videos natively in the Photos app and any media player.

Completely private — stays local

FFmpeg WebAssembly processes your video in-browser. No data is sent to any server, making it safe for sensitive recordings like meetings or demos.

Ready for social media & editing

MP4 is accepted by Instagram, TikTok, YouTube, Final Cut Pro, DaVinci Resolve, and virtually every other editing or sharing platform.

No server file size cap

Since conversion runs on your machine, you can convert large WebM files limited only by your device memory — far beyond typical upload-based service limits.

How this WebM to MP4 Converter works

Our WebM to MP4 Converter transforms open-source WebM video files into the universally compatible MPEG-4 (MP4) format. WebM files are common on the web but can be problematic for playback on iPhones, older devices, and some video editing software. This tool solves that compatibility issue instantly.

We use the industry-standard H.264 video codec and AAC audio codec during conversion to ensure maximum compatibility. The process runs entirely in your browser using WebAssembly technology, meaning your files are never uploaded to our servers.

Because no server upload is required, conversion starts immediately and is often much faster than cloud-based alternatives, especially for larger files. Once finished, you can verify the results with the built-in video player before downloading your new MP4 file.

After converting, reduce file size further with our MP4 Compressor.

How to use this WebM to MP4 Converter

Upload WebM

Drag and drop or select your WebM file.

Convert

Click to convert your video instantly.

Download MP4

Get your converted MP4 file.

Example Usage

A browser screen recording saved as WebM is converted to MP4 so it can be played on an iPhone and uploaded to social media.

Input

screen-recording.webm (VP9 video + Opus audio, 240 MB)

Output

screen-recording.mp4 (H.264/AAC, ~240 MB, plays on all devices)

Frequently Asked Questions

How do I convert WebM to MP4 on iPhone?

iPhones do not natively play WebM. Use our free online converter to transform your WebM file into MP4, which is fully supported by iOS Photos and media players.

Is there a file size limit for WebM conversion?

Because conversion happens locally in your browser, there is no arbitrary server upload limit. Performance depends mainly on your device processing power and RAM.

Will converting WebM to MP4 reduce quality?

Our tool re-encodes the video to MP4 (H.264), aiming for high fidelity. While any re-encoding can technically alter quality, the results are typically excellent and visually indistinguishable.

Why use MP4 instead of WebM?

While WebM is great for the web, MP4 is the universal standard for offline playback, editing software, and sharing on social media platforms like Instagram and TikTok.

Is this WebM to MP4 converter secure?

Yes. Unlike other sites that upload your video to a cloud server, our tool converts your file directly on your computer or phone, ensuring your data remains private.

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The WebM to MP4 Converter is maintained by CodeItBro. We aim to provide the best free developer tools on the web. If you have feedback or suggestions, please visit our contact page.

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