FLAC Metadata Viewer

About FLAC and its metadata

FLAC (Free Lossless Audio Codec) is an open, lossless compression format widely used by audiophiles, music libraries and archivists. Unlike MP3, FLAC preserves the original PCM audio bit-for-bit while still reducing file size by 30–60%. Every .flac file begins with a four-byte fLaC signature followed by a chain of metadata blocks: STREAMINFO, VORBIS_COMMENT, PICTURE, SEEKTABLE, CUESHEET, APPLICATION and PADDING. Each block describes a different aspect of the recording — together they form the full metadata picture of the track.

This tool decodes those blocks directly in your browser, so you can audit what your FLAC files reveal about you before sharing them online, sending them to a label, or submitting them to a streaming service.

How to view FLAC metadata

1. Select your file: drag & drop or pick a .flac file from your device. The file is opened locally — nothing is uploaded anywhere.
2. Inspect Vorbis comments: the parser reads TITLE, ARTIST, ALBUM, ALBUMARTIST, DATE, GENRE, TRACKNUMBER, DISCNUMBER, COMPOSER, ISRC, REPLAYGAIN_* and any custom tags.
3. Read the STREAMINFO block: view sample rate, bit depth, channel count, total samples, duration and the MD5 audio fingerprint.
4. Preview embedded artwork: if the file carries a PICTURE block, the cover art is rendered as a thumbnail.
5. Copy or export: press Copy to send a plain-text dump of every tag to your clipboard.

What FLAC metadata is displayed?

• STREAMINFO: minimum / maximum block size, minimum / maximum frame size, sample rate, channels, bits per sample, total samples, duration, MD5 signature.
• Vorbis comments: title, artist, album, album artist, year / date, genre, track number, disc number, composer, conductor, performer, lyricist, ISRC, label, catalog number.
• ReplayGain & loudness tags: REPLAYGAIN_TRACK_GAIN, REPLAYGAIN_ALBUM_GAIN, REPLAYGAIN_TRACK_PEAK, REPLAYGAIN_ALBUM_PEAK, R128_*.
• MusicBrainz identifiers: MUSICBRAINZ_TRACKID, MUSICBRAINZ_ALBUMID, MUSICBRAINZ_ARTISTID and other UUID tags used by Picard.
• Embedded artwork: PICTURE block (cover, back cover, artist photo, etc.) with MIME type, description and dimensions.
• Encoder & vendor string: which tool created the file (e.g. reference libFLAC 1.4.3).
• File info: name, size, MIME type, FLAC version, block list.

Why check FLAC metadata?

• Protect your privacy. Audio software, podcast hosts and DAWs sometimes embed your real name, email address or studio name in custom Vorbis tags.
• Verify lossless quality. The STREAMINFO block reveals true sample rate and bit depth — useful when buying "Hi-Res" downloads to make sure you didn't get an upsampled file.
• Prepare distribution. Aggregators like DistroKid, CD Baby and Bandcamp require correct ISRC, year and album-artist tags.
• Tag cleanup. Spot duplicate, empty or mis-spelled tags before importing a library into Roon, Plex, Jellyfin or Apple Music.
• Forensic checks. The MD5 audio signature lets you confirm the PCM stream has not been re-encoded.

FAQ

What is a Vorbis comment in a FLAC file?

Vorbis comments are the standard tagging format used inside FLAC, OGG Vorbis and Opus files. Each tag is a simple FIELD=value pair (e.g. ARTIST=Radiohead). FLAC stores them in a dedicated VORBIS_COMMENT metadata block right after the STREAMINFO block.

How is FLAC metadata different from MP3 ID3 tags?

MP3 files use binary ID3v1/ID3v2 frames at the start (or end) of the file. FLAC instead uses UTF-8 text Vorbis comments inside its native block structure. Field names are case-insensitive and you can add unlimited custom tags. There is no fixed "genre code" list — any string is valid.

Can the viewer show embedded cover art?

Yes. If the FLAC carries a PICTURE block (or, less commonly, a base64-encoded METADATA_BLOCK_PICTURE inside the Vorbis comments), the tool decodes it and displays a preview together with the picture type, MIME type, dimensions and colour depth.

Is my FLAC file uploaded to a server?

No. The whole analysis happens in your browser using JavaScript. Your file never leaves your device, so the tool is safe for unreleased masters, demos and private recordings.

Will the tool change my file?

No. This is a read-only viewer. To edit tags or strip metadata you can use a desktop tool like Mp3tag, MusicBrainz Picard or metaflac.

What does the MD5 audio signature mean?

FLAC stores an MD5 hash of the decoded PCM stream in STREAMINFO. After decoding, the player recomputes the hash and compares it with the stored one — a match proves the audio is bit-perfect and the file is not corrupted.

Why are some tags missing?

FLAC does not require any tags at all. If the artist or album field is empty, the encoder simply never wrote it. Many ripping programs (EAC, dBpoweramp, XLD) let you choose which tags to include during the rip.

How large a FLAC file can I open?

The viewer reads only the metadata blocks at the beginning of the file, so even multi-gigabyte 24-bit / 192 kHz files open instantly without loading the audio data into memory.

Does the viewer support FLAC inside Ogg or Matroska?

Native .flac files (with the fLaC stream marker) are fully supported. FLAC embedded in Ogg or MKV containers is detected but only basic file information is shown — for tag editing inside those containers use a dedicated tool.