Video converter online
Turn a video into an MP4 — it plays on any phone and in messengers — or a WebM for a website. If the picture is already H.264, the file is moved into an MP4 in seconds, with no loss of quality.
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How it works
- Choose a video or drop it into the frame below.
- Choose a format: MP4, WebM, GIF or WebP. The page tells you whether it needs re-encoding.
- Press “Convert” and download the file.
Formats and limits
| What | How |
|---|---|
| Opens | MP4, MOV, WebM, MKV, AVI, MPG, TS, 3GP, FLV, OGV, WMV, GIF |
| Saves | MP4 (H.264 + AAC), WebM (VP8 + Vorbis), GIF, WebP |
| Source | up to 200 MB and 30 minutes |
| No re-encoding | when the video is already H.264 — into an MP4 in seconds |
Your file stays with you
The video is not uploaded to lac.pics or anywhere else: your browser processes it, on your device. No sign-up needed. You need an account only to save the result to lacuna and send a link: then the file goes to “Uploads” in your account.
Questions
Is the video uploaded to a server?
The video is processed in this tab, on your device: the FFmpeg engine (WebAssembly) is downloaded from lac.pics with the first job — about 30 MB — and then runs locally. The file is not sent anywhere. It reaches lacuna only if you press “Save to lacuna” and sign in.
Why is one video ready in seconds and another takes long?
If the picture is already H.264, it does not need encoding again: the file is moved into an MP4 as it is. Otherwise the video is re-encoded on your device — about as long as it plays, or longer.
Which format should I choose?
MP4 to send a video or play it anywhere. WebM for websites. GIF and WebP for short animations without sound.
How do I make a video smaller?
There is a page for that — “Compress video”: presets, resolution and a before/after quality comparison.
More tools
- Compress videoMake it smaller and compare before and after.
- Trim videoCut parts out, join segments, mute, crop.
- Audio from videoMP3 or M4A from a video; audio to MP3.