Getting started
PreviewBound is a publishing tool that helps self-publishers, authors, and book formatters catch errors in their manuscripts and covers before uploading to platforms like KDP, IngramSpark, or Lulu. It checks margins, gutters, image resolution, spine width, bleed, and more — and includes Author Proof, a full page-turning preview of your book exactly as it will appear in print.
No account required. You purchase a session key from Gumroad, paste it on the activation page, and your session starts immediately. Your key and session are stored locally in your browser — nothing is tied to a login.
Interior manuscripts: PDF and DOCX. Cover files: PDF only. DOCX files are automatically converted to PDF for analysis. Make sure your DOCX is properly formatted before uploading for the most accurate results.
Free users can upload files up to 5 MB, week plan holders up to 20 MB, monthly plan holders up to 50 MB, and Pro Formatter plan holders up to 100 MB. Most text-only manuscripts are well under 10 MB. Heavily illustrated books or high-resolution files may be larger — compress images in your design tool if needed.
Pro Formatter plan holders can also use PreviewBound's built-in DOCX compression tool. To access it: analyse your DOCX manuscript first, then open Full Report — the compress option appears there once analysis is complete.
Sessions and plans
Your session starts when you activate your license key on the activation page — not at the time of purchase. This means you can buy a key in advance and activate it when you are ready to use it.
Each session key is bound to the first device and browser where it is activated. If you need to move your session to a different device, use the session reset page — we will send a transfer link to your purchase email.
1-Week ($3): Full interior and cover analysis, full Author Proof, and full report. Supports manuscripts up to 250 pages and 20 MB. Good for a single project.
1-Month ($7): Everything in the week plan, plus the book template generator and support for PDF manuscripts up to 400 pages and 50 MB. Best for active publishers.
Pro Formatter ($10 / 45 days): Everything in the monthly plan, PDF and DOCX manuscripts up to 600 pages and 100 MB, DOCX-first and setup checks, Auto-Fix, TOC Fix, EPUB conversion, DOCX compression, and shareable client report links. DOCX ebook preview is coming soon. Built for authors and professional formatters who work with editable manuscripts.
No. Sessions expire at a fixed time after activation regardless of how much you use them. Because the timer starts at activation (not purchase), you can wait until you are ready before activating.
All sales are final. Please review our Refund Policy for full details. If your key is not working due to a technical issue on our end, contact support@previewbound.com and we will resolve it promptly.
Interior analysis
The interior analysis checks: page margins (inside, outside, top, bottom), gutter size against KDP minimums for your page count, image resolution, trim size match, bleed settings, blank page detection, font embedding, and overall print readiness. For DOCX files it also checks section breaks, mirror margins, heading structure, and TOC formatting.
Word displays margins from the paper edge. KDP measures the printable content area relative to the trim size. If your document is set to a paper size larger than your trim size, what appears to be a 1-inch margin in Word may render as a much smaller margin on the printed page. Always set your Word document page size to match your exact KDP trim size before exporting to PDF.
Free users can analyse up to 100 pages. Week plan holders up to 250 pages. Monthly plan holders up to 400 pages. Pro Formatter plan holders can analyse up to 600 pages.
Cover analysis
The cover analysis checks: full cover dimensions against KDP requirements, spine width accuracy, bleed area, safe zones (front, back, spine), barcode reserve area, and whether any critical content falls outside safe boundaries. It also renders a full cover preview with all zones overlaid so you can see exactly where issues are — and how they will appear on print.
No — cover and interior analysis are independent. However, if you analyse your interior first, PreviewBound will use the page count and paper type from your interior to calculate the expected spine width for your cover. This gives you a more accurate spine check.
Flip-through and reports
Free users can view the first 10 pages in Author Proof. Any active One Week, One Month, or Pro Formatter session unlocks the complete manuscript. Upgrade on the pricing page for full access.
Pro Formatter plan holders can generate a private link to their full analysis report. The link can be sent to a client who can then view the complete interior and cover analysis — including issue details and cover preview — without needing a PreviewBound session key. Links expire after 72 hours.
Technical questions
The DOCX compression tool is available to Pro Formatter plan holders. To use it:
1. Upload your DOCX manuscript and run an interior analysis.
2. Once analysis is complete, open Full Report.
3. The compress option is available in the Full Report section.
Our compression engine reduces your DOCX file size by stripping unused styles, embedded fonts, and redundant metadata — and also optimises embedded images without visible quality loss. Your content and formatting remain intact.
Uploaded files are written temporarily to our server only for the duration of your analysis job and deleted immediately after. We do not retain, archive, or have long-term access to your manuscripts or cover files. See our Privacy Policy for full details.
PreviewBound checks against documented KDP guidelines. KDP's own review process may flag additional issues — especially with fonts, transparency, or embedded objects that cannot be fully detected without running KDP's own rendering engine. Use PreviewBound as a first-pass check, then review KDP's specific error message for anything it flags on upload. If you believe PreviewBound missed something, contact support@previewbound.com and we will investigate.
If you changed browsers, cleared your local storage, or are on a new device, go to the reset page and enter your purchase email. We will send a link to restore your session access to the current device.
Email us at support@previewbound.com. Include your purchase email and a brief description of the issue. We aim to respond within one business day.