Title and subtitle: 200 characters and a lock
According to KDP, the title is the field people search by most. Its field takes only the title from the cover. The subtitle is optional and follows the same rules.
«Together, your title and subtitle must be 200 characters or less.»
KDP does not accept in the title or the subtitle:
- Repeated generic words (‘books’, ‘journal’, ‘gifts’).
- References to other titles, other authors or trademarks, without authorisation.
- References to sales rank (‘bestselling’).
- References to advertisements or promotions (‘free’).
- Only punctuation, or only ‘n/a’, ‘none’ and the like.
- HTML tags.
«Customers are more likely to skim past long titles (over 60 characters)»
That last one is not a rule: it is a warning from KDP itself, and the checker treats it as a recommendation.
And the lock. Once the book is published, KDP locks the title and the subtitle. For paperbacks and hardcovers there is a 72-hour window from first publication; after that, changing them means publishing a new edition.
«You won’t be able to update your book’s title and/or edition once your book has been published, but you can publish it with the updates as a new title.»
The description: 4,000 characters, tags included
«Note that we have a limit of 4000 characters for the description.»
The KDP counter includes the HTML tags: a word in bold takes up seven more characters, those of <b> and </b>. The only tags accepted are:
- <br>, a line break.
- <p>, a paragraph.
- <b>, bold.
- <em> and <i>, italics.
- <u>, underline.
- <h4>, <h5> and <h6>, headings. <h1>, <h2> and <h3> are not supported.
- <ol> and <ul>, with <li>, numbered and bulleted lists.
And this is what KDP does not accept inside the description:
- Phone numbers, postal addresses, email addresses and URLs.
- Reviews, quotes or testimonials.
- Requests for reviews.
- Advertisements and promotional material.
- Time-sensitive information: tours, launches, seminars.
- Availability, price or other ways of buying the book.
- Unicode emojis.
- Keywords or tags.
- Pornographic, obscene or offensive content.
«Aim for a 150-word paragraph with sentences that are easy to scan.»
The 150 words are a suggestion from KDP, not a limit. The checker warns below 80 words and above 450: that is our own judgement.
KDP does not publish how many characters show before ‘Read more’, and the cut-off depends on the screen. That is why the checker gives no figure: it asks for the first sentence to stand on its own.
Keywords: seven boxes
«Use up to seven keywords or short phrases.»
«For best results, we recommend using phrases that are 2-3 words long.»
Banned. KDP says it removes content that does not comply with its guidelines:
- Other authors.
- Books by other authors.
- Sales rank (‘bestselling’).
- Advertisements or promotions (‘free’).
- Anything unrelated to the content of the book.
- HTML tags.
And this is what KDP recommends avoiding:
- What is already in the title, the subtitle or the author name.
- Words your categories already say.
- Opinions about quality (‘best novel ever’).
- What goes out of date (‘new’, ‘available now’).
- What is common to every book (‘book’).
- Spelling mistakes and variants of the same thing: singular and plural, with and without a space.
- Brands that are not yours.
- Quotation marks.
- Names of Amazon programmes (‘Kindle+’, ‘KDP Select’).
What does work, according to the same page: the setting, character types, theme and tone of the story. KDP also recommends searching Amazon for each keyword before using it and looking at what the search bar suggests.
«You can change keywords and descriptions as often as you like»
The KDP help speaks of ‘the character limit in the field’ without giving the figure. According to third-party sources, the form cuts off at around 50 characters per box: the checker flags it, but does not treat it as a rule or lower the grade for it.
Categories: three shelves
«During title setup, you’ll choose up to three categories from a list based on your primary audience and marketplace.»
They are chosen according to the book’s primary marketplace and audience. KDP recommends looking at where similar books sit, choosing categories that truly describe the book and balancing popularity and precision: not so broad that the book gets lost, nor so narrow that nobody passes by.
Changes can take up to 72 hours to show. KDP warns that it may remove or change a category unrelated to the book, and its support team does not recommend categories.
Categories are not the same in every store or in every format. That is why the checker only verifies how many there are and whether they go down to a subcategory; whether they exist in your store we check by hand in the pack.
The author page
The author page gathers your books and your bio. You create it free in Author Central, from the marketing tab in KDP, and the bio can be added in several languages. It is plain text, and Author Central recommends keeping it under 1,000 characters.
The KDP help in Spanish and in English does not agree on which stores the page can be edited in. Fill it in in Author Central and check how it looks in each store where you sell.
If you have used AI
«We require you to inform us of AI-generated content (text, images, or translations) when you publish a new book or make edits to and republish an existing book through KDP. […] You are not required to disclose AI-assisted content.»
KDP distinguishes between AI-generated content (the tool creates it, even if you edit it afterwards) and AI-assisted content (you create it and the tool helps you polish it). The first is declared on publishing; the second is not. The question refers to the book: its text, its images, cover included, and its translations.
No page of the help mentions the description in the listing. We write listings with AI directed and reviewed by a person, and we say so with every delivery. What has to be declared to KDP is for the author to decide and declare, according to these guidelines.
What nobody can promise you
«Neither Amazon nor KDP can guarantee that your book will display near the top of search results when finding your book.»
The same page explains that the order of results depends, among other things, on sales history, availability, how long the book has been on sale and its popularity. A well-made listing replaces none of that: it helps whoever arrives understand the book and gives KDP no reason to remove it.