Free online converter
Video to WebM Converter
MP4, MOV, WebM, GIF, JPG, PNG, WebP, HEIC, ZIP
Up to 100 MB free · 1 GB with Pro
HEIC, animated WebP input, PNG sequences and frame sequence export require Pro.
WebM is the format the web actually wants. It plays natively in modern browsers, streams without a heavy player, and stays far smaller than the same clip as MP4 — which is exactly why it shows up behind hero videos, product loops, and background motion on fast sites. LightBox turns your video into WebM right from your browser, with the controls that matter and none of the desktop-software overhead.
Drop in an MP4, MOV, or WebM and tune it before you export: pick a quality target, set the fps, trim to the moment you need, crop or resize to fit the slot it'll live in, and choose whether to keep the audio track or strip it for a silent loop. FFmpeg does the encoding on our servers, so you get a real, properly muxed WebM — not a renamed file that breaks on upload.
It's free, anonymous, and watermark-free. Your upload is processed and then auto-deleted within about an hour, so nothing lingers. No account, no install, no catch — just a WebM you can ship.
Why convert with LightBox
Lighter files, native playback
WebM is built for the web: it plays directly in modern browsers with no plugin and lands far smaller than the same clip as MP4. That means faster page loads for hero videos, product demos, and looping backgrounds — without trading away picture quality.
Encode controls that match the use case
A background loop and a tutorial clip don't need the same settings. Dial in quality, fps, and resolution, trim to the exact in and out points, crop to the frame you want, and keep or drop audio. You decide the tradeoff between size and fidelity instead of accepting a one-size export.
Real FFmpeg, not a rename
Conversion runs server-side through FFmpeg, so you get a correctly encoded WebM that uploads and plays everywhere it should. Files are processed and auto-deleted within about an hour, there's never a watermark, and you don't need an account to start.
Free forever. Pro when you need more.
Convert common formats free. Lifetime Pro adds more capacity and permanent hosting, with no subscription.
| Limit | Free | Lifetime Pro |
|---|---|---|
| File size | 100 MB | 1 GB |
| Per day | 4 files | Unlimited |
| Files kept | 1 hour | Forever |
| Batch | 1 file | 20 files |
| Queue | Standard | Priority |
50% off at launch · Paid once, yours for life. No recurring payments.
14-day money-back guarantee · secure checkout by Paddle
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