Free Amazon Backend Keywords Tool.Fill every byte. Waste none.
Turn real shopper searches into a Search Terms value that fits Amazon's 249-byte limit, with no repeats and no words your title already covers. Or paste the terms you use now and see what wastes space or breaks the rules.
- bytes filled, never over
- 249
- bytes filled, never over
- repeated words
- 0
- repeated words
- rule checks on your current terms
- 9
- rule checks on your current terms
- No signup, no paywall
- $0
- No signup, no paywall
Free Amazon Backend Keywords Tool
Build a Search Terms value that fills every byte without repeats, or check the one you already have.
One per line. Synonyms, spellings, uses, other languages.
0 phrases
Words already here are left out, Amazon indexes them already.
Add phrases above and your search terms appear here.
Need more phrases with competition data? Use the free Amazon keyword tool.
How to fill your backend search terms
- Pull real searches. Type your product in two or three words and press Pull keywords. You get the 40 phrases Amazon suggests most for it.
- Add what shoppers call it. Synonyms, regional words (torch and flashlight), spelling variants and uses: "camping", "gift for dad", "dorm".
- Paste your title and bullets. Those words are indexed already, so the tool leaves them out and spends the bytes on new ones.
- Trim. Click any word that does not describe your product. The next word moves up to fill the space.
- Paste into Seller Central. Edit listing, Keywords tab, Search Terms. Save, then check again in 72 hours by searching your ASIN plus a backend word.
What the checker looks for
| Problem | Why it hurts |
|---|---|
| Over 249 bytes | Amazon can drop the whole field, not just the end |
| Repeated words and plurals | Amazon indexes each word once, the repeat is wasted |
| Words from your title or bullets | Already indexed, so they take bytes for nothing |
| Banned claims (best, new, sale, free) | Against Amazon's search terms rules |
| ASINs | Not allowed in search terms |
| Filler words and commas | Ignored by Amazon, each one costs bytes |
| Accented letters and symbols | Take 2 or more bytes each, so the field fills faster than it looks |
Characters vs bytes
Seller Central counts bytes, not characters. "cafe" is 4 bytes, "café" is 5. On amazon.de or amazon.fr a field full of umlauts or accents can pass a character counter and still break the limit. This tool counts real UTF-8 bytes, the same way Amazon does.
Read the backend keywords guide for the full rules, find more phrases with the keyword tool, or run a free listing audit to see how your title and bullets use them.
Questions sellers ask
What are Amazon backend keywords?
Backend keywords are the words you enter in the Search Terms field in Seller Central (Edit listing, Keywords tab). Shoppers never see them, but Amazon indexes them, so your product can show up for searches that are not in your title or bullets.
How many bytes can the Search Terms field hold?
Amazon allows 250 bytes in the US, UK and EU marketplaces. If you go over, Amazon can ignore the whole field, so this tool stops at 249. Plain letters and digits take one byte, accented letters like é or ü take two, and many symbols take three.
Should I repeat words from my title in the backend?
No. Amazon indexes every word in your title, bullets and backend together, once. A word that is already in your title adds nothing in the backend and takes bytes you could use for a synonym. Paste your title and bullets into the tool and it leaves those words out.
Do I need commas between backend keywords?
No. Separate words with spaces. Commas, semicolons and slashes cost a byte each and do nothing for indexing. Word order and phrases do not matter either, so "garlic crusher" and "crusher garlic" match the same searches.
What words are not allowed in Amazon search terms?
Brand names you do not own, ASINs, temporary claims like new, sale or today, subjective claims like best, amazing or cheap, and offensive terms. Filler words like the, and, for and with are allowed but Amazon ignores them, so they only waste bytes.
Should I add plurals and misspellings?
Plurals usually not: Amazon matches singular and plural forms, so the tool counts press and presses as one word. Common misspellings and spelling variants (color and colour, grey and gray) are worth adding, because Amazon does not always correct them.
How long until backend keyword changes take effect?
Amazon usually indexes new search terms within 24 to 72 hours. To check, search Amazon for your ASIN plus one backend word. If your product shows up, the word is indexed.