What sample rate and bit depth should I upload to streaming services?

44.1 kHz at 24-bit integer PCM is safe everywhere. 44.1 kHz is the streaming standard. Never upload 32-bit float.

Are my audio files uploaded to a server?

No. All checks run locally in your browser by parsing file headers. No data is sent over the network and no account is required.

release-lint

Q: Why did DistroKid reject my song?

The most common cause is a 32-bit float WAV. Many DAWs export 32-bit float by default; the file plays fine locally but fails distributor ingest or is silently converted. Export 24-bit or 16-bit integer PCM instead. The second most common cause is cover art that is CMYK or smaller than 3000x3000 pixels.

Q: What size does Spotify cover art need to be?

Perfectly square, minimum 3000x3000 pixels, RGB JPEG or PNG. Spotify ingests art via your distributor, so the distributor limits apply as well.

Q: Why was my cover art rejected when it looks fine?

Usually the colour profile. JPEGs saved from Photoshop print presets are CMYK, which distributors reject, and they preview normally on screen. Other invisible causes are alpha channels in PNGs, progressive JPEGs, and indexed-colour PNGs. Convert to RGB and save as a baseline JPEG.

Drop your tracks and cover art. Find out exactly what your distributor will reject — before you spend a week waiting for the rejection email.

🔒 Runs entirely in your browser — your files are never uploaded

Drop your release folder here

or tap to choose files — WAV, FLAC, AIFF, MP3, M4A, JPEG, PNG

Check against

release-lint Pro — $19 once, yours forever

The free checker handles one distributor and up to 4 files. Pro is for shipping a whole release:

All 5 distributor specs at once — one grid, see who accepts it
Unlimited files — drop the entire album folder
Release-level checks — mixed sample rates, missing artwork, mono/stereo mismatches across tracks. The mistakes a per-file checker physically cannot catch.
Downloadable report — hand it to your mastering engineer or label

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What it actually checks, and why each one matters

Audio

Container (WAV/FLAC/AIFF/MP3/M4A) against what the distributor accepts · 32-bit float WAVs (the single most common silent rejection — most DAWs export float by default) · sample rate and bit depth · mono vs stereo · truncated files whose header claims more audio than the file contains · MP3 bitrate · suspiciously short tracks.

Cover art

Exact pixel dimensions and squareness · minimum and maximum size per distributor · CMYK JPEGs (exported from Photoshop's print presets — rejected or colour-shifted) · alpha channels in PNGs · progressive JPEGs · indexed-colour and 16-bit PNGs · file size limits.

How

It parses the actual file headers — RIFF chunks, FLAC STREAMINFO, AIFF COMM, MPEG frame headers, JPEG SOF markers, PNG IHDR — byte by byte, in your browser. No upload, no server, no account. Same engine as the release-lint CLI.

Honest limits

It reads headers, not audio content. It won't catch clipping, DC offset, loudness or silence at the top of a track. Distributor specs change; these profiles reflect published requirements and err toward the strict side so you don't get rejected.

Distributor spec cheat-sheet

The requirements these checks enforce. Strict side on purpose — a file that passes the strictest column passes everywhere.

	DistroKid	Apple Music	Spotify	Bandcamp
Audio formats	WAV, FLAC, AIFF, MP3, M4A	WAV, FLAC, AIFF	WAV, FLAC, AIFF	WAV, FLAC, AIFF
Bit depth	16 or 24-bit integer PCM. 32-bit float is rejected everywhere.
Sample rate	44.1 kHz standard, up to 192 kHz	44.1 or 48 kHz, up to 192 kHz	44.1 kHz standard, up to 96 kHz	44.1 kHz standard, up to 192 kHz
Cover art size	3000×3000 min, square	3000×3000 min, square	3000×3000 min, square	1400×1400 min, square
Art file size	20 MB max	no hard cap	no hard cap	10 MB max
Art colour	RGB JPEG or PNG. CMYK JPEGs are rejected everywhere — Photoshop's print presets export CMYK by default.

Why releases get rejected

Why did DistroKid reject my song?

By far the most common cause is a 32-bit float WAV. Ableton, Logic, FL Studio and Reaper all offer 32-bit float as an export option and several default to it. The file plays perfectly on your machine, so nothing looks wrong — it just fails on ingest, or gets silently converted with a level change. Export 24-bit (or 16-bit) integer PCM instead. The second most common cause is cover art that is CMYK or under 3000×3000.

What sample rate and bit depth should I upload?

44.1 kHz / 24-bit is the safe answer for streaming everywhere. 44.1 kHz is the streaming standard, so anything else gets sample-rate converted somewhere in the chain — which is fine when done well, but it is one more thing that can go wrong. Never upload 32-bit float.

What size does Spotify cover art need to be?

Perfectly square, minimum 3000×3000 pixels, RGB JPEG or PNG. Spotify ingests art through your distributor, so the distributor's limits apply too. 3000×3000 RGB JPEG clears every major platform at once.

Why was my cover art rejected when it looks fine?

Usually the colour profile. A JPEG saved from a Photoshop print preset is CMYK, which every distributor rejects — and it previews normally on your own screen, so there is no visual clue. Other invisible causes: an alpha channel in a PNG, a progressive-encoded JPEG, or an indexed-colour PNG. Convert to RGB and re-save as a baseline JPEG.

Are my files uploaded anywhere?

No. Every check runs in your browser — the page reads the file headers locally and never makes a network request with your data. There is no server to upload to and no account to create. You can load the page, disconnect from the internet, and it still works.