Does Amazon index KDP book titles automatically?

Yes. Amazon indexes your book title, subtitle, series name, author name and description automatically. Every significant word in these fields contributes to your book's keyword footprint without any action needed in the backend keyword boxes. This is why repeating title words in keyword boxes is a waste of your 350-character backend allowance: Amazon already knows those words from the title field and does not give additional weight for seeing them again in a keyword box.

What if my title contains my best keyword?

That is ideal: it means your most important keyword is already in the most prominent indexed field. You do not need to repeat it in a keyword box. Instead, use your keyword boxes to extend coverage into related phrases and sub-genre vocabulary that complements the title keyword. If your title contains 'cosy mystery', your keyword boxes should cover the specific tropes, settings, audience types and series descriptors that readers who love cosy mysteries also search for, not restate 'cosy mystery' again.

Should I repeat my series name in my KDP keyword boxes?

No. Amazon indexes your series name from the series field automatically. Repeating the series name in a keyword box wastes character space without adding any indexation benefit. The same principle applies to any word in your title, subtitle or author name: all are already indexed and should not be duplicated in keyword boxes. Use the keyword boxes exclusively for vocabulary not already present in any other field of your listing.

Should I repeat title words in KDP keywords?

You should not repeat title words in your KDP keyword boxes. Amazon indexes your book title automatically and uses those words to match your book against reader searches. Entering the same words again in a keyword box does not extend your keyword coverage, does not improve your ranking for those terms, and wastes the character space that could be used to make your book discoverable for entirely new reader search phrases. Amazon's indexation system reads every field in your book listing: title, subtitle, series name, author name, description and all seven keyword boxes. When Amazon encounters a word, it indexes that word once regardless of how many times and in how many fields it appears. A word in your title that also appears in a keyword box gives Amazon no additional signal. The indexation is identical with or without the repetition. The practical consequence is straightforward: every character you spend repeating a title word in a keyword box is a character that could have been used to introduce a new word that Amazon has not yet seen in your listing. Your title might contain 10 unique words. Your seven keyword boxes give you 350 characters to add entirely new vocabulary. Every repeated title word shrinks that new vocabulary budget without any return. Amazon's indexation of a KDP book draws on multiple fields automatically. Your book title is indexed in full. Your subtitle is indexed in full. Your series name, if you have one, is indexed. Your author name is indexed. Your book description is indexed, including any HTML-formatted content. All of these fields contribute to your keyword footprint without requiring any entry in the backend keyword boxes. This means that a thriller called 'The Silent Witness' with a subtitle 'A gripping psychological thriller' and a description that includes 'domestic suspense' is already indexed for those terms. Entering 'the silent witness', 'gripping' or 'psychological thriller' in a keyword box adds nothing. The keyword boxes exist specifically to cover the reader search vocabulary that does not naturally fit into your visible listing copy. Keyword boxes are for extending your indexation into reader search vocabulary that your visible listing does not cover. For a thriller, the title and subtitle might cover 'psychological thriller' and 'gripping'. The keyword boxes should then cover trope language ('unreliable narrator', 'missing persons', 'twisty ending'), audience language ('book club reads for women', 'thriller for fans of'), setting ('English village crime', 'London police procedural'), and emotional descriptors ('dark mystery', 'slow burn suspense') that readers use when they cannot name a specific book but know the type of story they want. The test for each keyword box entry is: does this include any word already present in my title, subtitle, series name or other keyword boxes? If yes, replace the repeated word with something new. If every word in the box entry is unique to your listing, it is making a genuine contribution to your keyword coverage.

Repeating title words in KDP keyword boxes wastes your 350-character allowance. Amazon already indexes your title. Learn what to put in the boxes instead.