Audio File Info

Audio File Info tells you what an audio or video file really contains. Drop in an MP3, WAV, FLAC, M4A, Ogg, Opus or a video and you get the container, the codec and its profile (AAC-LC or HE-AAC, for example), the exact duration, sample rate, channels and bit depth, and two bitrates: the one the file states and the one its audio data actually uses. For MP3s it also reads the frame headers, so you can see whether a file is constant or variable bitrate and which encoder made it.

Tags are shown in full: ID3v1 and ID3v2 in MP3s, Vorbis comments in FLAC and Ogg, iTunes atoms in M4A and the INFO chunk in WAV, with the cover art displayed. The tool then decodes the sound and measures its integrated loudness in LUFS, an approximate true peak, the sample peak and any clipped samples, and draws a small waveform.

Add as many files as you like. Each gets its own card, and a table compares them side by side, ready to export as CSV. MP3 tags can be removed losslessly, one file or a whole batch. Everything happens in your browser.

1. Press “Choose files” or drop audio or video files on the box.
2. Read each file’s card: Format, Loudness, Tags and Inside the file. Loudness appears once the sound has been measured.
3. With two or more files, compare them in the table at the top.
4. Press Export CSV to save the details, or “Copy details” on a card to copy one file as text.
5. For an MP3, press “Remove tags” to download a copy without its ID3 and APE tags.

• Container, codec and profile, duration, sample rate, channels and bit depth for MP3, WAV, FLAC, AIFF, M4A, AAC, Ogg, Opus, WebM and video files.
• Stated and actual bitrate, plus constant, variable or average bitrate and the encoder name for MP3s.
• All common tags and the cover art: ID3v1, ID3v2, Vorbis comments, MP4 atoms, FLAC metadata and WAV INFO.
• Integrated loudness in LUFS (EBU R 128), true peak from 4× oversampling, sample peak and clipped samples.
• How the loudness compares with −14, −16 and −23 LUFS targets.
• Technical extras: MPEG version and channel mode, WAV chunks, FLAC block list and audio MD5.
• Batch table with CSV export, and copy any card as plain text.
• Lossless MP3 tag removal for one file or a ZIP of many.

• If the actual bitrate is far below the stated one, the file was probably converted from a lower-quality source.
• A true peak above −1 dBTP can distort once a streaming service converts the file; turn it down a little before you upload.
• Many clipped samples in a row mean the recording was pushed too hard, and the distortion is baked in.
• Removing tags strips the cover art too. It is handy for privacy, or for players that choke on large tags.
• Export the CSV before clearing the list; the details are not saved anywhere when you leave the page.