Convert a video or a sound so it plays everywhere
Published · Updated 2 min read
Converting a video or a sound is not changing the extension in the file name. The content is re-encoded, that is rewritten in another format, and the weight of the file changes with the format and the quality chosen. This guide explains what to expect from each choice.
One video in five formats
A 20-second video of 1,280 by 720 pixels, recorded as MP4, weighs 14.7 MB. Its weight changes after conversion.
| Output format | Weight |
|---|---|
| WebM | 9,3 MB |
| MOV | 8,2 MB |
| MKV | 8,2 MB |
| AVI | 8,2 MB |
Conversion to WebM takes about 17 seconds, the others about a minute for 20 seconds of video. The longer the file, the longer the wait, since everything happens on your device.
What this means
The quality setting, from 10 to 100 with 80 by default, decides the level of detail and therefore the weight. In MOV, a quality of 30 gives 1.9 MB, 80 gives 8.2 MB and 100 gives 12.4 MB. At equal quality, the four formats give similar weights: a more detailed film weighs more, whatever the container. To lighten a file on purpose, the guide Lighten a video before sending it explains the bitrate setting.
One sound in five formats
For a 15-second voice as WAV, weighing 669 KB, the result depends on the format.
| Format | Weight |
|---|---|
| MP3 | 365 KB |
| OGG | 212 KB |
| AAC | 255 KB |
| FLAC | 353 KB, lossless |
Choosing
For sending to everyone, MP4 for video and MP3 for sound play almost everywhere, on a phone as on a computer. FLAC keeps exactly the original sound but weighs more. One point to remember: converting an MP3 to WAV or FLAC does not bring back the frequencies already removed, the file is just bigger.
When to convert
To play a video on an old device, publish it on a site that accepts only one format, or send a sound to someone whose player does not recognize yours: the right format avoids the "cannot play this file" message.
Check the result
- Play the file on the device that will receive it.
- Compare the weight and the quality with the source.
- Keep the original.
For a sound, see Convert audio.
Frequently asked questions
- Which video format plays everywhere?
- MP4 plays on almost every device. For sound, MP3 plays the same role.
- Does changing the file extension convert it?
- No. The content must be re-encoded, which is what the tool does. Simply renaming the file does not make it playable in the other format.
- Why is the conversion longer or shorter depending on the format?
- WebM is faster in the examples, about 17 seconds for 20 seconds of video, while the other formats take about a minute. Everything happens on your device.
- Does converting an MP3 to FLAC improve the quality?
- No. The frequencies already removed do not come back: the file is just bigger.