Methodology and disclosures

kdp123 is a reference directory, not a leaderboard. The goal is that a KDP publisher can check a tool's price, what it does for KDP, and how recent that information is, in one place.

What gets listed

• The product exists, is reachable, and is relevant to publishing on Amazon KDP.
• We can cite at least one source for the price and what it does. Entries without a source are not published.
• Listing is free. Payment, affiliate status or a vendor's request never decides whether or how a tool is listed.

What each entry shows

• Price. The model (free, free tier, one-time, subscription) and the lowest published price we found, with the date. Prices change often; the vendor site is the authority.
• KDP fit. Whether the tool produces KDP-ready files, which Amazon stores it supports where known, and whether it touches your KDP account. Tools that automate a KDP account can break Amazon's terms, so we flag that.
• Last checked. The date a person last confirmed the entry against its sources. Not a crawl date.
• Sources. The pages the facts came from. Where a source is the vendor's own page, the entry says so.

Conflicts of interest

• KDPTop. kdp123 is made by the same team as KDPTop. It is listed, labelled "Same team as kdp123", and described with the same fields as every other tool.
• Affiliate links. Some outbound links may be affiliate links. They are marked "Affiliate link" on the page and use rel="sponsored". Affiliate status is not used in any ranking or text.
• Vendor-published comparisons. Several comparison pages we cite are published by vendors or by sites that earn commissions. We use them for facts we can cross-check, not for verdicts.

Official rules

For anything about what KDP allows, Amazon's own help pages are the authority, not this site and not other publishers. Entries marked "Official Amazon" are first-party Amazon products.

KDP facts

Each KDP facts page answers one question about KDP's rules. Numbers are copied from Amazon's help pages, which are listed on the page; a fact page cannot be published without at least one Amazon source. Where a value differs by marketplace, the page says which marketplace it describes. Each page shows the date we last compared it with Amazon's pages.

Best-of lists

Each best-of list states its criteria before its picks, picks only tools that have a published listing here, and gives the reason for each pick. Prices and features in the lists come from those listings and their sources. These lists are editorial judgments made from published facts, not lab tests; we say so rather than claim hands-on testing we did not do. Tools we considered and left out are named with the reason.

Market data

The market data page summarizes open reports from KDPTop Research, made by the same team as kdp123. They are labelled as such, link to the full report and CSVs, and are released under CC BY 4.0 so anyone can check the numbers.

AI-generated content

KDP has its own disclosure requirements for AI-generated content and Amazon's review decision is final. Tools in the AI category are listed for what they do, not as a promise that output will be accepted.

Corrections

If something is wrong, open an issue or send a pull request with a source. Corrections are recorded on the changelog.

Data and licence

The data is published as JSON and CSV under CC BY 4.0. The site code is MIT licensed. Both are in the GitHub repository.