Free Audio Quality Checker Online
Detect fake lossless files instantly. Check if your WAV, FLAC, or AIFF is transcoded from MP3. The best free Spek alternative that runs in your browser.
Perfect for DJs checking track quality before gigs.
Drop your audio file here
or click to browse (MP3, WAV, FLAC, AIFF, M4A)
How the Audio Quality Checker Works
Like Spek, but online - no download required. Uses FFT spectrum analysis to detect frequency cutoffs.
Drop Your Audio File
Upload any audio format - MP3, WAV, FLAC, AIFF, M4A. Analysis runs locally in your browser with no file uploads.
FFT Spectrum Analysis
Our algorithm scans for frequency cutoffs that reveal lossy encoding - the telltale signs hidden when MP3s are converted to WAV or FLAC.
Instant Quality Verdict
Get the true quality rating: Genuine Lossless, High Quality (320kbps), Medium, Low, or Transcoded/Fake.
Why DJs Need to Check Track Quality
Before your next gig, make sure your tracks are club-ready.
Club Sound Systems Are Revealing
A 50kW Funktion-One will expose every artifact. Tracks that sound fine on headphones can sound muddy, harsh, or flat on big speakers.
Fake Lossless Files Are Common
Many "WAV" and "FLAC" files from download pools and bootleg sites are just transcoded MP3s. The format says lossless, but the audio isn't.
Beatport Isn't Always Safe
Some producers accidentally upload lossy masters. Even official releases can have quality issues if the source material was compromised.
Protect Your Reputation
Nothing kills a set faster than a track that sounds cheap. Verify quality before you play - your ears and audience will thank you.
Frequently Asked Questions
Everything you need to know about detecting fake lossless audio files.
What is a fake lossless or transcoded file?
A fake lossless file is an MP3 (or other lossy format) that has been converted to WAV, FLAC, or AIFF. While the file format is technically lossless, the audio data has already lost quality from the original lossy encoding. This is extremely common with bootleg downloads, free download pools, and poorly managed music libraries. The file size looks right, but the audio quality is permanently degraded.
How does the frequency cutoff detection work?
Lossy formats like MP3 remove high frequencies to reduce file size - this is called psychoacoustic encoding. A 128kbps MP3 cuts off around 16kHz, while 320kbps cuts around 19-20kHz. Genuine lossless audio (CD quality) extends to 22kHz. Even when converted to WAV or FLAC, these missing frequencies don't magically come back. Our tool uses FFT (Fast Fourier Transform) spectrum analysis to detect these cutoffs and reveal the true source quality.
Is this a Spek alternative?
Yes! Spek is a great desktop application for spectrum analysis, but it requires downloading and installing software. This audio quality checker provides similar functionality entirely in your browser - no download required. It's perfect for quick checks when you're organizing tracks, at a venue, or on any computer where you can't install software.
What frequency cutoffs indicate different quality levels?
Typical frequency cutoffs by quality: 128kbps MP3 cuts around 16kHz, 192kbps around 17-18kHz, 256kbps around 18-19kHz, 320kbps/V0 around 19-20kHz. Genuine lossless (WAV, FLAC, AIFF from CD or studio masters) extends to 22kHz or higher for hi-res audio. If your "lossless" file shows a cutoff at 16-20kHz, it's likely transcoded.
Why do some legitimate files show lower cutoffs?
Some genres and recordings naturally have limited high-frequency content. Acoustic recordings, lo-fi productions, or older masters may not have strong content above 18kHz even when genuine. Some producers also use MP3 samples in their productions, resulting in legitimate releases with encoded artifacts. The tool provides a confidence score to help account for these edge cases.
Is my file uploaded to a server?
Absolutely not. All analysis happens 100% locally in your browser using the Web Audio API. Your audio files never leave your device - they're not uploaded, not stored, not processed on any server. This makes the tool fast (no upload wait), private, and usable offline once loaded.
Which audio formats are supported?
The checker supports all common audio formats your browser can decode: MP3, WAV, FLAC, AIFF, M4A/AAC, OGG, and OPUS. For best results, use the same file you'd play in your DJ software. The tool analyzes sample rates up to 48kHz to ensure accurate detection on high-quality files.
Why Choose This Over Other Tools?
Compare the best audio quality checking tools for DJs and producers.
| Feature | Fabl | VerifAI Audio | Spek | Fakin' the Funk | auCDtect |
|---|---|---|---|---|---|
| Works in browser | |||||
| No download required | |||||
| Free to use | Paid | ||||
| Works on Mac, Windows, Linux | Windows | ||||
| Instant quality verdict | |||||
| Privacy (local analysis) | |||||
| Batch analysis | Sign up | ||||
| Detailed quality breakdown | Manual |
VerifAI Audio is another browser-based option but uploads files to servers. Spek is excellent free desktop software for manual spectrogram analysis. Fakin' the Funk is a paid desktop tool with advanced batch features. auCDtect is a free Windows tool using neural network detection.
Need Batch Analysis or Unlimited Checks?
Sign up free to get unlimited single-file checks. Pro users get batch analysis to check your entire library at once, plus BPM detection, key analysis, mix feedback, and more DJ tools.