Add Album Cover to FLAC Online

Complete the task in three clear steps

1. 1

   Choose the FLAC

   The browser follows the FLAC metadata block chain and reads only the metadata prefix before the audio frames.

2. 2

   Choose the artwork

   Upload JPG, PNG, or WebP. The image is prepared as a compact JPEG with a maximum long edge of 2000 pixels.

3. 3

   Write a new PICTURE block

   The metadata headers are rebuilt, the original audio slice is attached unchanged, and the picture block is inspected again.

What the browser changes—and what it leaves alone

FLAC stores album artwork in a PICTURE metadata block rather than an ID3 APIC frame. A picture block includes MIME type, dimensions, color depth, description, and the encoded image bytes. This editor creates a front-cover block and maintains a valid last-block flag across the metadata chain.

STREAMINFO remains first, and non-picture blocks such as Vorbis comments, seek tables, cue sheets, and application data are copied without interpretation. The lossless frames after the metadata section are used directly in the download.

When this tool is a practical fit

• Adding artwork to a lossless personal library
• Replacing several stale FLAC picture blocks with one front cover
• Keeping local browser privacy for large lossless recordings

Supported behavior and honest limits

• Standard native FLAC files beginning with the fLaC marker
• Preserves non-picture metadata block payloads
• Prepared image must fit the FLAC 24-bit metadata block length; the tool compresses normal artwork well below it