MP4 to WEBM Converter
Produce WebM (typically VP9/Opus) for HTML5 video embeds where WebM is preferred.
Choose a file or drag and drop
Drop your MP4 file here or
Choose file · Drag & drop · Public file link
- Processed on your device
- No conversion file stored on our servers
- Maximum file size: 100 MB
Conversion runs in your browser. Files are not uploaded to Format Convertly servers.
Processed on your device
No conversion file stored on our servers
Conversion Settings
Customize the output to match your needs.
Convert Quality
92%Output
Output options for this format are applied automatically during browser conversion. Drop your file above to begin.
Advanced settings
Additional Options
Quality or bitrate forces a re-encode. Width/FPS apply only when creating GIF or animated WebP.
How to Convert MP4 to WEBM
Add your MP4
Drop a MP4 file into the browser panel. Nothing is sent to a remote queue.
Confirm settings
Review optional quality/size settings, then confirm WEBM as the output.
Download WEBM
Convert locally and download the WEBM file when processing finishes.
Why Convert MP4 to WEBM?
Private by design
MP4 → WEBM runs in your browser. Files are not uploaded to a remote conversion queue.
Ready for the next step
Convert when a site, editor, or teammate expects WEBM instead of MP4.
Practical quality
WEBM: codec-dependent. Lossy targets trade size for speed — preview when it matters.
Wide compatibility
MP4 is commonly used for Social uploads and Website video.
MP4 vs WebM
A quick side-by-side before you convert — deeper comparison lives on the full guide.
| Feature | MP4 | WEBM |
|---|---|---|
| Compatibility | Best overall | Strong in Chromium/Firefox |
| Typical codecs | H.264/H.265 + AAC | VP8/VP9/AV1 + Opus |
| Best for | Social, phones, general delivery | Open web / HTML5 |
| Safari / iOS | Excellent with H.264 MP4 | Historically weaker — test |
| Open codec story | Mixed | Strong |
| Editors | Universal | Variable |
| Web embeds | Default choice | Great when you control the stack |
Choose MP4 when…
- Social uploads
- iPhone-first audiences
- Maximum device reach
- Client review copies
Choose WEBM when…
- HTML5 sites you control
- Open-codec policies
- Browser recordings staying WebM
- Alpha/sticker-style web video stacks
What happens to video quality?
Both MP4 and WEBM are typically lossy. A second encode can add generation loss — preview when fidelity matters. WEBM is a container. Video or audio quality depends on the codec packed inside, not only the file extension. Changing MP4 to WEBM re-encodes the media in the browser. It is not a lossless remux unless both sides share the same codec and container. MP4: MP4 itself does not define visual quality — H.264/H.265/AV1 and audio bitrates do. Re-encoding can reduce quality; remuxing keeps bitstreams when formats allow. WEBM: WEBM compression: codec-dependent. Lossy encoding discards some information to shrink files — re-saving repeatedly can accumulate artifacts. Typical size profile: Competitive with H.264 MP4 at similar visual settings. Quality note: Efficient at web bitrates; depends on VP9/AV1 encode settings
Tip
Converting from MP4 cannot restore detail already removed by lossy compression.
Does MP4 to WEBM reduce quality?
WEBM is typically lossy (codec-dependent). Use a higher bitrate when fidelity matters, and keep the MP4 master for archival.
WEBM format guide →Should I keep the original MP4?
Yes when you may need to re-encode later. MP4: MP4 is the safest video delivery format for phones, web, and social platforms. Shoot or edit in whatever your camera prefers, then provide an MP4 derivative for sharing.
MP4 format guide →MP4 · WEBM
Related converters MP4
Related converters WEBM
Frequently Asked Questions
More on quality loss: conversion quality guides · problem-solution guides
Does MP4 conversion reduce quality?
Changing containers can be lossless to quality if streams are copied. Re-encoding to another codec or bitrate can reduce quality.
Can you recover quality after converting?
Not from a lossy output alone. Return to the original master (or a better source). Converting to a lossless format does not resurrect discarded detail.
What is generational loss?
Damage that stacks when you decode and lossy-encode the same file over and over (for example JPG→edit→JPG). Edit from masters and export delivery formats once.
Where can I learn more about conversion quality?
Browse Format Convertly’s Quality guides for topics like whether conversion reduces quality, JPG↔PNG myths, WebP/MP3/MP4 tradeoffs, recovery limits, and generational loss — each links to the right converter.
Private?
Yes — encoding happens locally after the codec engine loads.
What is a MP4 file?
MP4 is a ubiquitous multimedia container usually holding H.264/H.265 video and AAC audio. MP4 is the safest video delivery format for phones, web, and social platforms. Shoot or edit in whatever your camera prefers, then provide an MP4 derivative for sharing.
What is a WEBM file?
WEBM is an open web media container typically carrying VP8/VP9/AV1 video and Opus audio. WebM is built for HTML5 video with open codecs — common for browser recordings and site backgrounds. Convert to MP4 when you need maximum device and editor compatibility, especially in Apple-heavy workflows.
Is MP4 to WEBM free?
Yes. Format Convertly conversions are free to use in your browser with no signup required.
Ready to Convert Your Files?
MP4 to WEBM privately in your browser.