TopTool
MP4→WEBM

MP4 to WebM

MP4 to WebM is a free online video converter for changing MP4 files into WEBM files. MP4 to WebM accepts 1 MIME type, returns video/webm, includes 1 setting, and runs in your browser on the device.

Drop .mp4 file here

or click to choose

Options

Key facts

Input
1 format: MP4 (video/mp4)
Output
WEBM (video/webm)
Runtime
your browser on the device
Settings
1 control: Video bitrate
File mode
1 input file creates 1 output file
Cost
$0, no account required

How to use MP4 to WebM

  1. 1

    Open your MP4 file

    Drop your MP4 file onto the page, or click to browse and pick one from your device.

  2. 2

    Choose options

    Adjust the conversion options to suit your needs. Defaults work well for most inputs.

  3. 3

    Convert and download

    Click Convert. Your WEBM file is ready to download in seconds.

MP4 to WebM details

First, MP4 to WebM reads MP4 source files and prepares WEBM output for the video workflow. Next, The visible controls are Video bitrate. Additionally, Files and text stay in the browser session.

Re-encode an MP4 file as a WebM container with VP9 video and Opus audio. WebM is the open, royalty-free format used by YouTube and most browsers; great for embedding video on the web with small file sizes. The conversion runs locally via ffmpeg.wasm, so your video never leaves your device. Sources taller than 1080p are automatically downscaled to 1080p so the browser doesn't run out of memory mid-encode. Performance depends on your CPU: expect roughly real-time encoding (a 5-minute 720p video may take 1;2 minutes). For best results keep inputs under ~500 MB.

Common searches

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Related tools

Tools that work with the same formats — most users open one of these next.

VideoOnline

WebM to MP4

Convert WebM video to MP4 (H.264 + AAC) — free online, no upload.

WEBM→MP4
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Compress Video

Shrink a video file by re-encoding to H.264 with a quality preset — free, in-browser.

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MP4 to AAC

Extract the AAC audio track from an MP4 video — free online, no re-encode.

MP4→AAC
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MKV to MP4

Convert MKV (Matroska) video to MP4 (H.264 + AAC) — free, runs in your browser.

MKV→MP4
VideoOnline

AVI to MP4

Convert AVI video to MP4 (H.264 + AAC) — free, runs entirely in your browser.

AVI→MP4

Frequently asked

What is MP4 to WebM?

MP4 to WebM is a free online video converter for changing MP4 files into WEBM files. MP4 to WebM accepts 1 MIME type, returns video/webm, includes 1 setting, and runs in your browser on the device.

What files does MP4 to WebM accept and create?

MP4 to WebM accepts MP4 files (video/mp4) and creates WEBM files (video/webm). The page includes 1 setting: Video bitrate.

Do my files and data stay private?

Yes. MP4 to WebM runs entirely in your browser using your device's CPU. Files and text are never uploaded to our servers, so your data stays private.

How do I use MP4 to WebM?

Open MP4 to WebM, drop in your MP4 file, choose any options, and click Convert. Your browser does the work locally and produces a WEBM file you can save right away.

What is the maximum file size for MP4 to WebM?

Because MP4 to WebM runs in your browser, the maximum size depends on your device's available memory. Most modern phones and laptops handle files up to a few hundred MB without issues.