Trusted by 503+ Authors

Fix Your KDP Margin & Bleed Errors.

The professional-grade PDF utility for indie authors. Upload your manuscript and we handle the math — tuned for Amazon KDP acceptance, using the same standard paperback trims you will see at IngramSpark, Lulu, Blurb, and similar print-on-demand services (always confirm final dimensions in your printer's dashboard).

13,105+ Pages Optimized99.8% Amazon Acceptance RateAverage Fix Time: 42 Seconds

Beyond the first fix

Automatically generate back matter that sells your next book.

Readers who finish your book are your warmest audience — give them a polished About the Author, an Also By catalog page, and a newsletter signup with an optional QR code, all at standard interior bleed sizes so you can merge into your paperback PDF in the browser.

  • Turn one-time readers into subscribers and series buyers — without hiring a layout designer for every release.
  • Built locally in your browser; you choose the signup URL (https or mailto only). Pair with our PDF inspector before upload.
  • Included with an active free trial or any paid plan that unlocks subscriber PDF tools — same gate as our journal composer.

Discoverability

Multi-book authors use back matter as a sales surface inside every print copy — not an afterthought.

Free trial

Try InkAlign free for 7 days

Up to seven print-ready KDP interiors — full pipeline, no credit card. Sign in, then tap Activate on the trial page to start your window when you're ready.

Stop wasting hours on manual formatting.

Rejected

Spine text clipped in the gutter

Approved

Aligned spine & safe margins

How it works

Step 1

Upload

Drag your manuscript PDF.

Step 2

Scan

We check 15+ KDP print requirements instantly.

Step 3

Fix & Download

One click to fix all errors and get your print-ready file.