How to convert an MP3 into a lighter MP3
If you have an MP3 that’s too large and you want to send it quickly via WhatsApp, email or upload it to the cloud, the solution is to recompress it with a lower bitrate. This way you get a lighter MP3 file that still plays fine on phones, car stereos and TVs.
On this page we’ll show you how to use our online MP3 compressor step by step, which bitrate to choose, what file size to expect per minute and some tips to avoid losing more quality than necessary.
How to compress an MP3 (step by step)
- Open the MP3 compressor in your browser.
- Upload the
.mp3file you want to make lighter. - Select a lower bitrate: for voice, 64–128 kbps is usually enough; for music, 128–192 kbps.
- Click Convert and wait a few seconds while the MP3 is recompressed.
- Download your new lighter MP3 and save it to your device or cloud storage.
The converter works on Android, iPhone, Windows and macOS from the browser, without installing anything. You only need enough free space to download the new MP3.
Which bitrate should I choose?
The bitrate (kbps) determines both the quality and the size of your MP3. The higher the bitrate, the better the audio but also the heavier the file.
| Use | Recommended bitrate | Notes |
|---|---|---|
| Voice notes / meetings | 64–96 kbps (mono) | Very clear speech and small files, ideal for sharing. |
| Podcasts | 96–128 kbps | Balanced quality for long recordings. |
| Background music | 128–160 kbps | Good enough for most casual listening. |
| Music you care about | 192 kbps or more | Heavier MP3s, but more detail. |
Quick rule: if the original MP3 is already 128 kbps and you only need to save a bit of space, try 96 kbps. For speech-only recordings, 64 kbps in mono is often more than enough.
Approximate size per minute
These are indicative values (CBR). The actual size may vary slightly.
| Bitrate | MB per minute (approx.) | Typical use |
|---|---|---|
| 64 kbps | ~0.47 MB | Very light voice (long recordings, WhatsApp/email). |
| 96 kbps | ~0.70 MB | Podcasts / voice with extra margin. |
| 128 kbps | ~0.94 MB | Clear voice and basic music. |
| 160 kbps | ~1.17 MB | Music with a bit more detail. |
| 192 kbps | ~1.41 MB | Music where you care more about quality. |
Common use cases
- Shrinking a long podcast or interview so it takes less space on your phone.
- Sending an MP3 via WhatsApp or email without hitting attachment limits.
- Keeping several versions of a song: a lighter one for mobile and a heavier one for local backup.
- Saving space on a USB stick for your car or TV by lowering the bitrate slightly.
Tips to preserve quality when recompressing
- Avoid multiple re-encodes: each MP3 to MP3 step adds more loss. Try to convert only once to the final bitrate.
- Use mono for voice: if your tool allows it, mono halves the data without hurting speech clarity.
- Don’t go too low for music: under 96 kbps, many listeners will start to notice artefacts in songs.
- Normalize volume afterwards (for example with Audacity) if your compressed MP3 ends up too quiet.
- Keep the original file if possible, in case you want to recompress it differently in the future.
Online • Free • Works on mobile and desktop
Frequently asked questions
What bitrate is best for voice recordings?
For voice-only content, 64–128 kbps in mono is usually enough. It keeps the speech clear and the MP3 very light, perfect for sending by WhatsApp or email.
Will I lose quality when recompressing an MP3?
Yes. Every time you recompress a lossy format (MP3 to MP3) you lose a bit of quality. That’s why it’s better to do a single conversion to the bitrate you want, instead of several successive ones.
Does this MP3 compressor work on mobile?
Yes. You can open the tool from Android or iPhone in your browser, upload the MP3, and download the lighter version directly to your phone.
What happens to my files after I upload them?
A responsible converter will process your MP3 files temporarily only to recompress them and then delete them after a short time. They should not be used for other purposes or shared with third parties.