Raw recording in. Submission-ready out.
Upload your audiobook chapter. Greenlit removes clicks, pops, and mouth noise, masters it to ACX spec — loudness, peaks, noise floor, format — and tells you exactly what it fixed.
Free diagnostic, no account · 8-point ACX report · Results in under 60s
chapter-01.wav
Quality report · 2 issues found
- RMS−18.3 dBFSPass
- Peak−1.8 dBFSWarning
- Noise Floor−54.2 dBFail
- Sample Rate44.1 kHzPass
- Bitrate192 kbpsPass
Scope of work
You bring the performance. We handle the rest.
Greenlit isn't just a checker. It runs an AI enhancement pass that cleans up your recording, then masters it to the exact specs retailers require — and shows you everything it fixed.
Cleanup powered by Dolby.io · mastered to ACX targets with FFmpeg
You bring
- A clean recording
- Consistent narration
- Opening & closing credits
- One chapter per file
We handle
AI cleanup
- Background noise reduction
- Low-frequency rumble removal
- Click & pop removal
- Plosive reduction (P & B bursts)
- Sibilance / de-essing (harsh S sounds)
- Mouth-noise cleanup
Mastering & format
- Loudness normalization (RMS)
- True peak limiting
- Head & tail silence padding
- Compliant CBR MP3 export
- Full 8-point compliance report
Three steps. Zero audio knowledge.
Upload your chapter
Drop in your finished recording — WAV, MP3, FLAC, or AIFF. No account needed for a free diagnostic. One chapter at a time, up to 120 minutes.
We run the pipeline
An AI enhancement pass removes clicks, pops, mouth noise, and hiss. Then mastering normalizes loudness, limits peaks, pads silence, and exports a compliant MP3 — measured before and after.
Download master + report
Get your ACX-compliant MP3 plus a full report showing every measured value, with a clear pass or fail on each spec.
The 8-point check
Every spec ACX checks — measured in seconds.
RMS
Loudness sits right in the −18 to −23 dBFS sweet spot ACX wants.
Numbers, not guesswork
The exact measurements retailers reject for — caught before you submit.
RMS Loudness
−18.3
dBFS · in spec
True Peak
−1.8
dBFS · we lower it
Noise Floor
−54.2
dB · too loud
How it compares
Studio-grade mastering, without the studio bill.
| Mastering method | Estimated cost | Time | Trade-offs |
|---|---|---|---|
| Human mastering engineer | $700–$1,200 | 3–7 days | Expensive, slow, must share files |
| Fiverr freelancer | $100–$300 | 1–3 days | Variable quality, IP exposure |
| Manual in Audacity | Free | 2–10+ hours | Steep learning curve, high rejection risk |
| Greenlit Audio (monthly) | $15/mo + $8/hr over | ~2 minutes | AI cleanup + mastering, report-backed |
87%
lower cost than studio mastering
8
ACX spec checks on every file
<2 min
average processing time per chapter
Pricing
Know the cost before you start.
Diagnostic checks are always free. Pay only when you process.
Monthly
5 finished hours included.
- Full cleanup + mastering
- $8 / hr overage
- Pause anytime — hours stay put
- Free diagnostic always included
Annual
70 finished hours included.
- 2 months free + 10 bonus hours
- Hours never expire
- Saves $60 vs monthly
- Everything in Monthly
Pay as you go
No subscription. Best for one-off books.
- Pay per project
- Same cleanup + mastering engine
- No monthly commitment
Going on break between projects? Pause instead of cancel— keep your history, pay nothing while you're away.
FAQ
Common questions.
Does Greenlit remove clicks, pops, or mouth noise?
Yes — this is one of the biggest differences between Greenlit and simpler mastering tools. Your file goes through an AI enhancement pass that reduces background noise, removes clicks and pops, and cleans up mouth noise before mastering. You still want a clean take — it's not a substitute for good recording — but the minor artifacts that cause rejections or distract listeners get cleaned up automatically.
Will my file definitely pass ACX after processing?
Greenlit guarantees the measurable technical specs: loudness, true peak, noise floor, sample rate, channel count, bit rate, and silence. ACX also runs a human quality review that listens for things like echo and manuscript accuracy — recording-quality issues need to be fixed before you upload. No mastering tool can fix a bad take.
Does it work for platforms besides ACX?
Yes. The same technical spec that passes ACX — loudness targets, noise floor, sample rate, and format — is what Findaway, Google Play, Kobo, and Apple Books all require. Get your file right once and it’s ready everywhere.
What is a "finished hour" and how is it billed?
A finished hour (PFH) is the duration of your processed audio, rounded to the nearest 0.1 hours. A 45-minute chapter is 0.8 finished hours. Monthly subscribers get 5 PFH included; extra hours are $8/hr. Pay-as-you-go is $10/hr with no monthly fee.
Do I need a subscription to check my file?
No. The diagnostic check — a full 8-point ACX report with actual measured values — is free, with no account required. You only pay when you want Greenlit to process and fix the file.
Do I need a DAW to use Greenlit?
Not for mastering — that’s what Greenlit replaces. You’ll still need a way to record and edit your narration (fix mistakes, add credits). Once your edited recording is ready, Greenlit handles the mastering step.
Ready to get your audio greenlit?
No account. No card. Upload a chapter and see your ACX compliance report in under 60 seconds.
Run a free ACX check