MP3 vs MP4: what is the difference?
The short answer: MP3 is an audio format, MP4 is a video format. If you want to listen, MP3 is usually enough and far smaller. If you want to watch, you need MP4.
The names look alike, which causes confusion, and many people also call any MP4 file with music “an MP3”. This guide explains the real differences and helps you choose before you convert.
MP3 and MP4 in one table
| MP3 | MP4 | |
|---|---|---|
| Content | Audio only | Video and audio (a container) |
| Typical use | Music, podcasts, lectures, voice notes | Films, clips, tutorials, anything to watch |
| File size | Small | Several times larger, depending on resolution |
| Plays on | Practically every device | Practically every device with a screen |
| Quality setting | Bitrate: 128–320 kbit/s in ClipZen | Resolution: from 144p up to your account's limit |
How big are the files?
An MP3 is easy to calculate: size = bitrate × duration. For a 3-minute track, 128 kbit/s gives about 2.9 MB, 192 kbit/s about 4.3 MB, 256 kbit/s about 5.8 MB and 320 kbit/s about 7.2 MB. An MP4 of the same length is usually several times larger and depends mostly on the resolution. ClipZen shows an estimated size next to each choice before you convert.
When to choose MP3
- You only need the sound: music you are allowed to keep, podcasts, lectures, interviews.
- You have little storage or a slow connection.
- You want to listen on a device without a screen, such as a car stereo or a basic player.
When to choose MP4
- The picture matters: tutorials, demonstrations, presentations, sport or dance clips.
- You want to edit or share a video.
- You want to watch offline on a phone, tablet or TV.
Ready to try? See the guides for the video to MP3 converter and the video to MP4 converter. For audio quality, read the MP3 bitrate guide.
Ready to convert a link?
Paste the link of a video you have the right to convert, choose MP3 or MP4, and download the file.
Open the converterThe converter itself is currently in French: the buttons are named MP3, MP4 and “Choisir la qualité ou le format” (choose quality or format).
Frequently asked questions
Is MP4 better quality than MP3?
They are not directly comparable: MP4 carries video (and audio), MP3 carries audio only. For music alone, an MP3 at 192–320 kbit/s is usually more than enough.
Can an MP4 file contain only audio?
Technically yes, but the MP4 files ClipZen produces contain video and audio. Choose MP3 for audio only.
Which format is smaller?
MP3, by a wide margin.
Can I turn an MP3 back into a video?
No. MP3 has no picture. Convert the link to MP4 if you want video.
Related guides
- Video to MP3 converter: extract the audio from a linkPaste a video link, choose 128–320 kbps and download the audio as MP3. Free to try, no software to install, for content you have the right to convert.
- Video to MP4 converter: pick the resolution you needConvert a video link to MP4 (H.264 + AAC) and pick the resolution that fits your device and storage. See the estimated file size before you convert.
- MP3 bitrate guide: 128, 192, 256 or 320 kbps?What MP3 bitrate means, how it affects sound and file size, and which of 128, 192, 256 or 320 kbps to choose for music, podcasts and archiving.