How can we help?
Search the FAQ, browse what each preset does, or reach a real person — Greenlit is run by someone who's spent years in audiobook QC.
Getting started
Upload a file and run your first free check.
ACX requirements
What each preset masters your file to.
Advanced mode
Adjust cleanup strength and preview before/after in Studio.
Mouth De-Click plugin
Install and use the free plugin (VST3 + AU) in your DAW.
Spec Meter plugin
Install the free live ACX spec meter (VST3 + AU) and read its meters.
Billing & credits
How credits work and what packs cost.
Will my file definitely pass ACX after processing?
We master to every ACX technical requirement — loudness, true peak, noise floor, head/tail room tone, and format — so the technical bar is met. ACX also has human reviewers who listen for performance, mouth noise, and consistency. That part is up to your narration, not the numbers — but a clean, on-spec file gives you the best possible shot.
What's the difference between a free check and processing?
A free check is a read-only diagnostic: we measure your file against the spec and show you exactly what would pass or fail — nothing is changed and nothing is charged. Processing actually cleans and masters the file, then delivers a submission-ready WAV and MP3. Processing spends credits; the check never does.
How do credits work?
1 credit = 1 minute of processed audio. You only spend them when you process a file, never on a free check, and they never expire. Your first 60 minutes (up to 3 files) are free to start.
My file has said "Processing" for a while — is it stuck?
Almost certainly not. Our GPU workers spin down when idle and take a few minutes to warm back up, so the first job after a quiet spell can sit in Processing longer than usual. It keeps running even if you close the tab, and the dashboard tracks it live. If it's been over 30 minutes, reach out and we'll look.
What can I upload, and how long can it be?
WAV, AIFF, or FLAC are preferred (lossless), but MP3 and M4A are accepted too. Files can be up to 120 minutes — ACX caps individual chapters at 120 minutes, so split longer recordings into chapters and upload each one.
Can I use Greenlit inside my DAW?
Yes — Greenlit Studio, our desktop app, includes a VST3 plugin that runs the same check and mastering engine inside Reaper and Audacity. Studio installs it with one click and it activates through your Studio sign-in, so there's no separate download or login — and your audio still never leaves your machine. Free spec checks work in the plugin too; a Studio plan unlocks processing. Available on both macOS and Windows — see the Studio page for details.
Do you keep my files?
Your uploads and processed masters are stored only long enough to deliver them, then removed on a rolling retention window. You can also delete a processed file yourself from the dashboard at any time.
What each mastering preset does
Every preset runs the same cleanup pipeline underneath; only the numeric target and delivery format change.
ACX Audiobook
For narrators submitting finished chapters to ACX, Findaway, or any audiobook retailer.
What happens to your file
First, an AI cleanup pass (DeepFilterNet3) removes background hiss and recording-room noise, and a click/pop pass catches mouth noise and stray transients that a normal declicker misses.
Next, gentle compression evens out the loudest and quietest moments so your narration sits at a consistent level, and the silence at the start and end of the file is trimmed to a clean, natural length — with a touch of room tone blended in rather than dead digital silence.
Finally, your file is mastered to the loudness and peak targets ACX requires, and exported as a mono 192kbps MP3 — see the exact numbers below.
Mastering targets
- Loudness target: -23 to -18 dBFS — the average loudness of your recording from start to finish — the same measurement ACX checks for audiobooks.
- True peak ceiling: -3 dBFS — the loudest single instant allowed, to keep playback from clipping or distorting.
- Sample rate: 44,100 Hz.
- Output format: WAV — an uncompressed master, the standard for broadcast/agency delivery.
Broadcast Commercial
For TV and radio commercials, and other spots delivered under CALM Act loudness rules.
What happens to your file
First, an AI cleanup pass (DeepFilterNet3) removes background hiss and recording-room noise, and a click/pop pass catches mouth noise and stray transients that a normal declicker misses.
Next, gentle compression evens out the loudest and quietest moments, and the silence at the start and end of the file is trimmed to a clean, natural length — with a touch of room tone blended in rather than dead digital silence.
Finally, your file is mastered to CALM Act loudness and peak targets and exported as a WAV master — see the exact numbers below.
Mastering targets
- Loudness target: -26 to -22 LUFS — the average perceived loudness across the whole spot or recording, measured in LUFS — the standard broadcast/streaming loudness unit.
- True peak ceiling: -2 dBFS — the loudest single instant allowed, to keep playback from clipping or distorting.
- Sample rate: 48,000 Hz.
- Output format: WAV — an uncompressed master, the standard for broadcast/agency delivery.
Agency / Corporate VO
For corporate voiceover, e-learning, explainer videos, and IVR/phone prompts.
What happens to your file
First, an AI cleanup pass (DeepFilterNet3) removes background hiss and recording-room noise, and a click/pop pass catches mouth noise and stray transients that a normal declicker misses.
Next, gentle compression evens out the loudest and quietest moments, and the silence at the start and end of the file is trimmed to a clean, natural length — with a touch of room tone blended in rather than dead digital silence.
Finally, your file is mastered to a loudness and peak target suited for corporate/web delivery and exported as a WAV master — see the exact numbers below.
Mastering targets
- Loudness target: -20 to -16 LUFS — the average perceived loudness across the whole spot or recording, measured in LUFS — the standard broadcast/streaming loudness unit.
- True peak ceiling: -3 dBFS — the loudest single instant allowed, to keep playback from clipping or distorting.
- Sample rate: 48,000 Hz.
- Output format: WAV — an uncompressed master, the standard for broadcast/agency delivery.
Advanced mode in Greenlit Studio
In the Greenlit Studio desktop app, the file screen has an Advanced panel that lets you adjust the cleanup and hear the result before you process. It's a Studio desktop feature — you won't find it here in the browser.
- Mouth de-click (Off / Light / Standard / Strong) — how sensitively the mouth-noise cleanup hunts for clicks and lip smacks. Default: Standard.
- Noise reduction (Off / Light / Standard) — how much background noise is removed. Default: Standard.
- De-esser (Off / Auto / Strong) — softens harsh S sounds. Default: Auto.
The defaults are exactly what Greenlit already does when you never open the panel — leaving it closed changes nothing about your master. Setting a control to Off disables only that adjustable cleanup — every master still gets Greenlit's base polish (rumble filter, click safety net, mastering to spec).
To hear a setting before committing, click a suggested spot — or anywhere on the waveform once a check has run — and a ~40-second section renders in seconds. Then toggle instantly between Original and Processed with both waveforms on screen: amber is your original, green is the processed version. Previews are free and unlimited, and nothing is written until you process.
Still stuck?
If a file failed a check you don't understand or something else is off, ask a real person — not a support queue.
Contact support