🖼️

Free · In-browser · No upload

FLAC Cover Art Editor.

Add or change one JPEG or PNG front cover in a single FLAC or 2–50 files at once — locally, without re-encoding audio.

Before-and-after illustration of FLAC Cover Art: FLAC and image becomes Artwork-ready FLAC through Embed or extract art. — **Before → process → after**Review original and selected cover, then inspect the FLAC delivery.

FILE STRUCTURE MAP

FLAC Artwork Panel

Choose current artwork without transcoding FLAC audio. A decoded JPEG/PNG replaces the type-3 front cover only after its read succeeds. Back artwork, comments and encoded FLAC frames are retained in a single file or current batch ZIP.

Open the full signal breakdownCurrent cover, exact metadata limits and ZIP checks

FLAC and image
Start with the right material
Adding one JPEG or PNG front cover across a FLAC delivery without transcoding the music.
Embed or extract art
Understand the transformation
The page waits for the current source and validated JPEG/PNG, replaces only type-3 front-cover PICTURE blocks, retains other metadata payloads and encoded audio, and builds a current single FLAC or sequential STORE ZIP with a manifest.
Artwork-ready FLAC
Verify the usable result
One edited FLAC, an extracted image, or one ZIP containing every accepted FLAC plus a machine-readable manifest.

Picture block

Where this workflow stops

Single-file input is capped at 48 MiB on mobile or 128 MiB on desktop. Batch input is capped at 64 MiB or 160 MiB respectively, with the same per-file limits and separate peak-memory guards; malformed files are rejected and each FLAC metadata block must fit the 16 MiB format limit.

THREE-PASS CHECK

Verify artwork, manifest and the target player

Wait for the new cover to validate; single-file and batch exports are unavailable while it reads.
Inspect the saved file in the intended player: front cover changed, other artwork and comments retained.
Unzip a batch, compare the manifest file mapping and cover properties, and keep the original FLAC files.

Input: One FLAC, or a batch of 2–50 valid .flac files, plus one decodable JPEG or PNG cover.
Batch output: A STORE ZIP with uniquely named FLAC files and flac-cover-art-batch-manifest.json.
Preservation: Non-front artwork, other metadata-block payloads and encoded audio bytes are copied byte-for-byte.

How to add one cover to multiple FLAC files

Choose Batch add/change cover and select 2–50 .flac files. Wait for the browser to scan each current metadata chain locally.
Review every file status and remove rejected or malformed rows before export. Confirm the accepted queue is the delivery you intend.
Choose one JPEG or PNG and wait for its current filename and decoded dimensions. Export is unavailable while a newer cover reads; Retry or choose another image if validation fails.
Download the STORE ZIP with uniquely named FLAC outputs and flac-cover-art-batch-manifest.json. Unpack it, compare the current cover and file mapping, and inspect artwork and playback in the intended player.

How it works: the editor validates each FLAC metadata chain, replaces only valid PICTURE blocks whose picture type is 3, keeps all other metadata payloads in source order and appends the original encoded audio payload unchanged. Multiple old front covers become one selected front cover.

Honest limits: single-file mode accepts up to 48 MiB on mobile or 128 MiB on desktop. Batch mode accepts 2–50 files, up to 64 MiB total input on mobile or 160 MiB on desktop, with the same per-file limits and a separate conservative 256 MiB / 512 MiB peak-memory preflight. The complete PICTURE block must be smaller than 16 MiB. Malformed files are rejected rather than repaired.

Worked example: replace a front cover across an album

Choose Batch add/change cover, load the album FLAC files and review each row. Choose your JPEG or PNG through Choose batch cover. Wait for its filename and dimensions, then download the ZIP. The accepted image replaces all valid type-3 front covers with one front cover per output; back covers, artist images, Vorbis comments and unrelated metadata payloads retain their bytes. The original encoded FLAC stream is copied, not decoded or transcoded.

Edit one FLAC or extract its original cover

Single FLAC accepts one local source; Try a demo FLAC offers a known example. Extract original front cover downloads the artwork already embedded in that current source, not an unfinished replacement. Choose replacement cover shows the new image only after JPEG/PNG validation succeeds. Download FLAC with new cover then writes a separate delivery file; the original is not overwritten. This tool does not edit FLAC comments or remove artwork without a replacement.

Resolve a pending or failed cover choice

Selecting another source removes its predecessor's extract and save actions immediately, including during demo loading. Selecting another cover clears the previous replacement and retires an old batch receipt; exports stay unavailable until the current image is accepted. Cancel read, Escape, a workflow change or leaving the page discards unfinished work. Retry selected file or choose another image to recover. Native disk I/O may still finish after logical cancellation; the editor does not start overlapping reads in the same owner. A physically finishing batch read retains its existing memory-safety lock. Wait for its controls to unlock before switching to single mode or starting another batch; a refused replacement selection cannot leave the previous ZIP current.

Verify the recipient's copy

Keep the original FLAC files. For a batch, unpack the ZIP and compare output filenames and cover properties with its manifest; do not send the ZIP without checking its contents. Open a downloaded FLAC in the target player and inspect front artwork, comments and other picture roles, then check playback independently. A player's cached thumbnail is not a byte-preservation check. The PICTURE block has a 24-bit length boundary: this editor reserves its fields as well as the image bytes below 16 MiB. Oversized, malformed or undecodable inputs are refused; they are not silently repaired.

FLAC Cover Art: quick answer and technical limits

Quick answer: A single-file and 2-to-50-file FLAC front-cover editor that preserves the encoded audio and unrelated metadata byte for byte.

Best for: Adding one JPEG or PNG front cover across a FLAC delivery without transcoding the music.
How it works: The page waits for the current source and validated JPEG/PNG, replaces only type-3 front-cover PICTURE blocks, retains other metadata payloads and encoded audio, and builds a current single FLAC or sequential STORE ZIP with a manifest.
What you get: One edited FLAC, an extracted image, or one ZIP containing every accepted FLAC plus a machine-readable manifest.

Know before you use it: Single-file input is capped at 48 MiB on mobile or 128 MiB on desktop. Batch input is capped at 64 MiB or 160 MiB respectively, with the same per-file limits and separate peak-memory guards; malformed files are rejected and each FLAC metadata block must fit the 16 MiB format limit.

Public browser workflow evidence

Question: Can the tool add a front-cover picture while preserving the compressed FLAC audio payload byte for byte?

Observed result: The exported FLAC contained a type-3 front-cover picture and retained the original compressed audio payload byte for byte.

Evidence boundary: The fixture covers one valid FLAC structure and one front-cover replacement path, not every malformed or unusual metadata layout.

Network observation: No audio-payload or cross-origin requests were observed during this published workflow.

Open the public benchmark, method and fixture →

Privacy: Selected audio is processed in this browser and is not uploaded to AudioWrench. Normal page assets can still be requested as described in the privacy notice. Privacy details →

FAQ

How do I add the same cover to multiple FLAC files?

Choose Batch add/change cover, select 2–50 valid .flac files, choose one JPEG or PNG, remove any rejected rows, then download the ZIP. The same image is embedded as the type-3 front cover in every output.

Does changing FLAC cover art re-encode the audio?

No. FLAC stores artwork before the encoded audio stream. This tool rebuilds the metadata chain, then copies the original audio payload byte-for-byte without decoding or re-encoding it.

What image formats and batch sizes are supported?

Cover art must be a decodable JPEG or PNG whose complete FLAC PICTURE block is smaller than 16 MiB. Batch mode accepts 2–50 FLAC files and also enforces device-aware input, per-file and estimated peak-memory limits shown in the tool.

Will back-cover artwork and FLAC comments be preserved?

Yes. Replacement removes only valid type-3 front-cover PICTURE blocks. Back covers, artist images, other PICTURE roles, Vorbis comments, unknown metadata-block payloads and the encoded audio payload are copied byte-for-byte.

What is included in the batch ZIP?

The ZIP uses STORE method 0 and contains one uniquely named .flac output per accepted source plus flac-cover-art-batch-manifest.json. The manifest records the operation, cover properties, file mapping, preservation guarantees and the memory preflight.

Are my FLAC files or cover image uploaded?

No. Selected FLAC files and cover art are read in browser memory and are not uploaded to AudioWrench. Normal page assets can still be requested as described in the privacy notice.