Audio bitrate checker
Check the bitrate of an MP3 or any audio file in your browser — nothing is uploaded.
Drop an audio file and its bitrate is read from the file itself: from the header in front of every MP3 frame, or from an M4A’s index of samples. Then the page listens to half a minute of it and finds the highest frequency the sound reaches, which tells you what the file really is.
Bitrate, CBR and VBR
Bitrate is how many bits a second of sound uses: 128 kbps for most downloads, 320 kbps at the top of MP3, 1411 kbps for CD-quality WAV. Constant bitrate (CBR) spends the same on every second; variable (VBR) spends more where the music is busy. An MP3 states its bitrate in front of every frame, so CBR or VBR here is read, not guessed from the file size.
Is 320 kbps better than 128?
On good headphones it usually is: at 128 kbps cymbals and reverb can turn swirly. But a higher number only helps if the sound was there to start with, and converting a 128 kbps file to 320 makes it bigger, not better.
How a fake 320 kbps MP3 gives itself away
An MP3 encoder cuts off the highest frequencies before it starts, lower for lower bitrates: LAME, the most common encoder, cuts a 128 kbps file at about 17 kHz and a 320 kbps file at about 20 kHz. Re-encoding never puts back what was cut. So a “320 kbps” MP3 whose sound stops at 17 kHz was made from a 128 kbps one — and the chart shows exactly where yours stops. A recording with no high notes to begin with stops early too, so read it as evidence.
How to use it
- Add an MP3, M4A, WAV, FLAC, OGG or other audio file.
- Read the bitrate, CBR or VBR, the sample rate and the channels.
- Look at where the sound stops to see what the file really is.
Why use this tool
Completely private
Everything runs inside your browser. Your files and text are never sent to a server.
Free, with no limits
No sign-up, no watermarks and no cap on how many times you can use it.
Instant results
There is no upload or queue to wait for, so results appear as fast as your device can work.
Works on any device
Runs in any modern browser on phone, tablet or desktop. Nothing to install.
Frequently asked questions
- How do I check the bitrate of an MP3?
- Drop it here: the bitrate, CBR or VBR and the sample rate appear at once, read from the MP3’s own frame headers. A music player’s file info shows the bitrate too, but not whether the file was made from a lower one.
- Is 320 kbps better than 128 kbps?
- It can be, on good equipment: 320 kbps keeps more of the high frequencies and fewer artefacts. It is only better if the file was encoded from a good source — a 128 kbps file converted to 320 sounds exactly like the 128 kbps file, in a bigger file.
- Can a 320 kbps MP3 be fake?
- Yes. A file converted from 128 kbps to 320 kbps reports 320 but keeps the 128 kbps cut-off at around 16 to 17 kHz. This page shows where your file’s sound stops and says which bitrate that matches.
Related tools
Media info
See what is actually inside a video or audio file — codec, resolution, bitrate, length.
Video bitrate checker
Check the bitrate of a video in your browser — the file never leaves your device.
Convert audio
Change an audio file between MP3, WAV, OGG, M4A and FLAC.
Compress audio
Make an audio file small enough to send, without making speech hard to follow.
Voice message to MP3
Turn a Telegram or WhatsApp voice note into a normal MP3.
Frame rate checker
Check the frame rate of a video in your browser — the file never leaves your device.