AAC Validator
Drop any .aac file to instantly check its integrity. Validates the ADTS bitstream sync words, reports MPEG version, AAC profile (LC, Main, SSR, LTP), sample rate, channel configuration, frame count, and duration. Also reads embedded ID3v2 metadata tags. Nothing leaves your browser.
AAC File
Drop a .aac file here, or
Supports .aac files up to 200 MB
⛔
Wrong file type — only .aac files are supported. You dropped a file.
Validation Errors
Warnings
✓ Valid AAC
ID3v2 Metadata Tags
How It Works
1
Drop your AAC fileDrag it onto the drop zone or click "browse" to select it from your device.
2
ADTS bitstream analysisThe validator scans for the ADTS sync word (
0xFFF), then reads every frame header to verify sync word consistency, frame lengths, and audio properties. It also checks for an ID3v2 tag block before the bitstream.3
Review the reportGet a pass/fail result plus full stats: AAC profile, MPEG version, sample rate, channels, frame count, duration, and any embedded ID3v2 metadata tags.
What Gets Validated
- ADTS sync word — every frame must begin with the 12-bit sync pattern
0xFFF. Missing or corrupt sync words indicate a damaged or non-AAC file. - MPEG version — the ID bit reports whether the stream uses MPEG-4 AAC (0) or MPEG-2 AAC (1).
- AAC profile — extracted from the 2-bit profile field: Main, LC (Low Complexity), SSR (Scalable Sample Rate), or LTP (Long Term Prediction). LC is by far the most common.
- Sampling frequency — decoded from the 4-bit sampling frequency index. Common values: 44100 Hz, 48000 Hz, 22050 Hz.
- Channel configuration — the 3-bit field maps to Mono, Stereo, 5.1, 7.1, etc.
- Frame length & count — the 13-bit frame length field in each ADTS header is verified. Total frame count and duration are derived from this.
- ID3v2 tags — raw AAC files often carry an ID3v2 block before the ADTS data. The validator reads title, artist, album, year, genre, track, and more.
🔒 Privacy & Security
All validation is performed locally using the Web File API and JavaScript ArrayBuffer. Your audio file is never sent to a server. Suitable for private recordings, unreleased masters, or any sensitive audio content.
Related Guides & Tutorials
Guide
The Complete Guide to Aac Validating: Everything You Need to Know
What the validator checks, how to interpret results, and best practices for AAC audio file integrity.
TutorialHow to Use the Aac Validator: Step-by-Step Tutorial
A practical walkthrough of validating AAC files in your browser with real examples.