whatsmybitrate

Reading Room

Articles

Format-by-format guides to checking your own files, plus notes on lossless audio, bitrates, and why I built this thing in the first place.

Guides

How to tell if a FLAC is really lossless

Five clues that separate a genuine lossless file from an MP3 in a FLAC wrapper — and how to read the difference on a spectrogram.

Guides

How to tell if a WAV was upscaled

A WAV's size tells you nothing about its quality. Spotting inflated sample rates, padded bit depths, and WAVs made from MP3s.

Guides

How to check an MP3's real bitrate

Why 320 kbps on the label doesn't mean 320 kbps of music, and how CBR and VBR muddy the reading.

Guides

How to check an AAC or M4A file

An .m4a can be lossy AAC or lossless ALAC — same extension, different worlds. Plus how HE-AAC fakes its high frequencies.

Reference

Audio glossary

Bitrate, Nyquist, dither, transcoding, SBR and the rest — defined in plain language, with no marketing attached.

Reference

How to view a spectrogram

Nyquist frequency, sample rate, and the peak-to-Nyquist ratio — with a reference spectrogram for every format: MP3, AAC, Ogg, Opus, FLAC, ALAC, WAV and AIFF.

Fundamentals

What is a truly lossless file?

Lossless gets thrown around a lot. Here's what it actually means — and why a FLAC file isn't always what it claims to be.

Fundamentals

What are the benefits of lossless audio?

Beyond the marketing: the real, practical reasons lossless is worth caring about (and when it isn't).

Listening

Can you tell the difference between lossy and lossless?

The honest answer, the science of ABX testing, and why your brain loves to trick you.

Sources

Where can I find lossless audio (legally)?

Streaming services, download stores, and the CDs you forgot you owned — a roundup of legitimate lossless sources.

Gear

What type of hardware is best for lossless?

Headphones, DACs, stereo systems, and where your money actually makes a difference.

Behind the scenes

How does WhatsMyBitrate work?

A peek under the hood: spectral analysis, Nyquist frequencies, and how we sniff out upscaled files.

Behind the scenes

What was the motivation to start WhatsMyBitrate and make it open source?

It started with a suspicious "FLAC" file. Here's the story.