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Guide 04

Keywords: KDP's 7 slots and how to fill them

You get seven keyword fields, fifty characters each, three hundred and fifty total. No commas. No brand names. Here's how to use them without wasting them.

Last updated Apr 21, 2026v1 · pending Spellbound

KDP gives you seven "keyword" fields. Together they're 350 characters of metadata you control: not visible to readers, but fed into Amazon's search index. Most authors treat them like tags. That's wrong. They're closer to long-tail SEO copy.

The hard rules

  • Seven fields, 50 characters each. Including spaces. Amazon truncates anything over 50.
  • Phrases, not lists. Use spaces to separate words inside a field. No commas. Amazon treats spaces as natural separators and indexes on the combination, not on the individual words — but putting commas in wastes characters and gives you nothing back.
  • Each word once across all seven. If "dystopian" is in field 3, putting it again in field 5 does nothing. The index is set-based, not count-based.
  • Don't repeat words from your title or subtitle. Those are already indexed with more weight than the keyword fields. Duplicating them is dead space.
  • No brand names. "Colleen Hoover", "Harry Potter", "Tolkien" — Amazon can and will strip these, and repeat offences can flag the book.
  • No Amazon program names. "Kindle Unlimited", "Audible", "Amazon bestseller", "free" — same treatment.
  • No misleading claims or price/promo hints. "#1 bestseller", "99 cent sale", "limited time" — strip.
  • Nothing offensive or obviously spammy. Misspellings of popular searches (harriy potter) get flagged.

What to put in instead

Think about how a real reader would describe the book to a friend who hasn't read it. What sub-genre signals would they use? What tropes? What feel? Those phrases — written the way a reader would type them into Amazon search — are your keywords.

For a novel like Spellbound (sci-fi, dystopian arcology, first contact, looming apocalypse), the instinct is to put:

Field 1: sci fi first contact novel                   (30)
Field 2: dystopian arcology future                    (30)
Field 3: space opera hard science fiction             (37)
Field 4: post apocalyptic survival adventure          (41)
Field 5: literary sci fi for fans of the expanse      (45)
Field 6: cli-fi climate dystopia                      (26)
Field 7: single author short stories                  (NO — wrong genre, don't do this)

Several things to notice about those:

  • No commas. Amazon indexes on each word plus the phrase.
  • Phrases readers actually type ("for fans of the expanse" is a common search pattern).
  • No brand names. "For fans of the expanse" works because "The Expanse" is a show, not a KDP author identifier — but use this sparingly and never with a specific person's name.
  • Each field reads like a real phrase a person would say.
  • No words repeated across fields. "sci fi" appears only in fields 1 and 5 because the two phrases are doing different work.

The research you should do

Spend an hour on this. It pays more than spending it on formatting.

  1. Search your genre's top-10 books on Amazon. Note the phrases Amazon's "People also search for" shows under each.
  2. Type genre phrases into the Amazon search bar and watch the autocomplete. Those are real search volumes.
  3. Write out 20+ candidate phrases. Pick the seven that feel both accurate (your book actually delivers this) and searchable (readers type this).
  4. Lay them out in a 7 × 50-character grid. Cut until each fits.

Things authors do wrong

  • Treating the fields as seven lists separated by commas. Wastes 10–15% of the character budget.
  • Stuffing the fields with single words. "dystopian fantasy romance sci-fi thriller" reads to Amazon as a jumble, not a searchable phrase.
  • Repeating words from the title. "Spellbound" already gets you every search containing "spellbound"; don't put it in keywords too.
  • Chasing the most popular phrase regardless of fit. Your book shows up in search, reader clicks, reader bounces because it's not what they wanted — Amazon's conversion signal punishes you for the mismatch.

The short version

  1. Seven fields × 50 chars. No commas. Each word once across all seven.
  2. No brand names, no Amazon program names, no promo copy.
  3. Don't repeat title/subtitle words.
  4. Write real phrases readers would type.
  5. Use "for fans of [widely-known book or show, not a specific author name]" sparingly.
  6. Research Amazon autocomplete for your genre before deciding.

Anthony's take

TODO — revise with Spellbound specifics. The Spellbound slots above are drafts off the back of the existing blurb. Once the book is up and we've watched a month of search-term data in KDP reports, this section shows which phrases actually brought readers and which were guesses — with the replacements that stuck.

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