MP4 to WebM

MP4 to WebM Converter — Fastest Free, No Watermark

Typical 30-second 1080p clip converts in 15–30 seconds end-to-end
QUICK ANSWER

The fastest free MP4 to WebM converter online. Drop an MP4 (or .mov), get a WebM you can drop straight into an HTML5 video tag, Google Slides, or an open-source player. Native server-side ffmpeg encodes VP8 + Vorbis with no browser memory ceiling. Up to 500 MB, no signup, no watermark.

  • Native server-side ffmpeg
  • Up to 500 MB per file
  • VP8 + Vorbis output
  • Accepts .mp4 and .mov
  • No watermark
  • No signup
  • Files deleted within 24h

Files are deleted from our server within 24 hours.

Trusted by creators at startups, agencies, and Fortune 500 teams.
Free forever — no signup, no watermark, no length cap.

How it works

  1. 1

    Drop your MP4 (or MOV) file

    Drag any .mp4 or .mov file in or click to choose. Files up to 500 MB are supported.

  2. 2

    Click Convert to WebM

    Native ffmpeg on our server decodes the H.264 (or HEVC) video stream and re-encodes to VP8 using libvpx at constant-quality CRF 30. Audio is re-encoded to Vorbis.

  3. 3

    Download your WebM

    The finished WebM is delivered through Bunny CDN. Drop it into an HTML5 video tag, a Google Slides embed, or any FOSS-friendly player.

Why this is the fastest MP4 to WebM converter on the web

VP8 / libvpx is significantly heavier than H.264 — browser ffmpeg.wasm encoders crawl on it and crash on anything longer than a couple of minutes. We rebuilt the pipeline: presigned upload to the nearest Backblaze B2 POP, native server-side ffmpeg with libvpx at CRF 30, output delivered through Bunny CDN. A 30-second 1080p clip typically clears in 15–30 seconds.

Why convert MP4 to WebM?

Three real reasons. One: WebM is the format the browser's MediaRecorder API produces, so if you are building anything that round-trips through that pipeline, WebM is the native shape and MP4 is the friction. Two: some open-source video players and FOSS ecosystems prefer WebM because VP8 and Vorbis are royalty-free where H.264 and AAC are not. Three: Google Slides accepts WebM embeds natively, so if your destination is a Slides deck you can skip the MP4 conversion entirely.

VP8 vs VP9 — what we encode and why

This free MP4 to WebM converter uses VP8 (libvpx) with constant-quality CRF 30 and Vorbis audio. VP8 is the most compatible WebM codec — supported everywhere that accepts WebM at all, including every major browser and most open-source players. VP9 would give better compression at the same quality, but it is significantly slower to encode and the compatibility gain is minimal for typical screen recordings and short clips.

Sister tools

Going the other direction? WebM to MP4 converter handles browser-recorded WebM into universal MP4 — much faster than this direction because H.264 encoding is lighter than VP8. For other container hops: MOV to MP4 converter, AVI to MP4 converter, MKV to MP4 converter. Shrinking a finished MP4 before this conversion? Video compressor. Or skip the dance entirely: Clipy records straight to a hosted link, so you do not have to pick a container at all.

Why this is the fastest MP4 to WebM converter on the web

VP8 / libvpx encoding is significantly heavier than H.264 — single-threaded WebAssembly encoders crawl on it, and they cap out at ~2 GB tab memory so anything longer than a couple of minutes routinely crashes. We rebuilt the pipeline. Your MP4 uploads via a presigned URL to the nearest Backblaze B2 storage POP, native ffmpeg on our server runs libvpx with constant-quality CRF 30 (the right balance for screen recordings and short clips), and the output is delivered through Bunny CDN. A 30-second 1080p clip typically clears in 15–30 seconds end-to-end — much faster than browser ffmpeg.wasm on the same machine, and able to handle files that the browser path simply cannot.

Why convert MP4 to WebM?

Three real reasons. One: WebM is the format the browser's MediaRecorder API produces, so if you are building anything that round-trips through that pipeline, WebM is the native shape and MP4 is the friction. Two: some open-source video players and FOSS ecosystems prefer WebM because VP8 and Vorbis are royalty-free where H.264 and AAC are not. Three: Google Slides accepts WebM embeds natively, so if your destination is a Slides deck you can skip the MP4 conversion entirely.

VP8 vs VP9 — what we encode and why

This converter uses VP8 (libvpx) with constant-quality CRF 30 and Vorbis audio. VP8 is the oldest and most compatible WebM codec — supported everywhere that accepts WebM at all, including every major browser and most open-source players. VP9 would give better compression at the same quality but is significantly slower to encode, and the compatibility gain is minimal for typical screen recordings and short clips. For most use cases, VP8 is the right choice.

Common questions

Is this MP4 to WebM converter really free?

Yes — free with no usage caps, no account, and no watermark on the output. The conversion runs on our server, and we cover the cost as part of the broader Clipy free toolset.

How do I convert MP4 to WebM?

Drop your .mp4 file onto this page, click Convert to WebM, then click Download. No install, no account required. The output is a VP8 + Vorbis .webm file ready for HTML5 video or any WebM-compatible player.

Will my WebM be smaller than the MP4 I started with?

Often, especially for screen recordings. If the MP4 was already aggressively compressed, the WebM can be similar in size or larger because any re-encode has container and codec overhead.

Why is this conversion slower than WebM-to-MP4?

VP8 / libvpx encoding is significantly heavier than H.264. Native ffmpeg on a server still finishes in 15–30 seconds for a 30-second 1080p clip — much faster than browser ffmpeg.wasm, but slower than H.264 transcoding either direction.

Can I use this WebM in HTML5 video tags?

Yes. VP8 + Vorbis inside WebM is supported by modern browsers as a first-class HTML5 video format. It is a great fallback or primary source for self-hosted video players.

Is my file private?

We accept the file over a presigned upload to our B2 storage POP, run libvpx on our server with native ffmpeg, and serve the result through Bunny CDN. The source and output are deleted within 24 hours. No signup is required.

How big a file can I convert?

Up to 500 MB. Because we run native ffmpeg on the server (not browser ffmpeg.wasm), there is no browser memory ceiling — files that crash other online WebM converters work here.

More free tools

WebM to MP4 converter
Turn browser-recorded WebM into MP4 anyone can play.
MOV to MP4 converter
Batch MOV to MP4 with trim, crop, compression, music, and text overlays.
AVI to MP4 converter
Modernize old AVI files (DivX, Xvid, MP3 audio) to clean MP4.
MKV to MP4 converter
Convert MKV files to MP4 free — no upload, no watermark.
Video compressor
Shrink a video for Slack, email, or cheaper hosting.
MP4 to GIF converter
Make GIFs from videos with batch, crop, splice, effects, reverse, and loop controls.
GIF to MP4 converter
Batch GIFs to MP4 with audio, text overlays, effects, crop, repeat, and quality controls.
MP4 to MP3 converter
Pull the audio track out of any video as MP3.
MP4 to MOV Converter
Convert MP4 to MOV for Final Cut Pro, QuickTime, and legacy post workflows.