How to Convert a Video's Format (MP4 / WebM / MOV)
Last updated: June 12, 2026
“This video won't play.” “It won't upload.” Most of the time the cause is the video's format. This guide shows you how to convert a video so it works anywhere — no software, free, nothing uploaded.
What is a video format?
Video files come in formats (containers) like MP4, WebM, MOV, AVI and MKV, shown by the file extension. Different formats play on different devices and apps, so a file that works for you may not open for someone else. The most widely supported is MP4 — when in doubt, use MP4 and it plays and uploads almost everywhere.
How to convert the format
With our format converter, just drag & drop. Your video is never uploaded — it's processed in your browser.
- Choose a video (drag & drop).
- Pick the output format (MP4 / WebM / MOV / GIF / MP3).
- Click “Convert.”
- Download the converted file.
Which format should I choose?
| Goal | Recommended |
|---|---|
| Send / post to social / save | MP4 |
| Embed on a website | WebM |
| Use as an animated image | GIF |
| Just want the audio | MP3 |
See also MP4 vs WebM for the differences.
If conversion fails
A few codecs (AV1, HEVC) may not decode in the browser, in which case you'll see an error. Also, this converter uses a powerful engine and can't run from a local file (file://) — use it on the live site (https://).
FAQ
- Q. Will MP4 play almost anywhere?
- A. Yes. MP4 (H.264) is very widely supported across devices, apps and social platforms.
- Q. Does quality drop?
- A. It re-encodes, but with proper settings the visual difference is minimal.
- Q. Is my video uploaded?
- A. No. Everything is processed in your browser and never sent to a server.