Backend Keywords
Also known as: Search Terms, Hidden Keywords
Backend keywords are the hidden "Search Terms" field in a listing where sellers add extra keywords that help the product get indexed without appearing on the public page.
Backend keywords live in the "Search Terms" field of the listing's Keywords section in Seller Central. They are not visible to shoppers but are indexed by Amazon's search engine, letting you capture synonyms, misspellings, alternate spellings, and use-case terms that would clutter the title or bullets.
Amazon caps the Search Terms field at 250 bytes per listing; anything beyond the limit is ignored. Best practices: no commas needed (spaces separate terms), do not repeat words already in your title/bullets (redundant indexing), avoid competitor brand names and ASINs (a policy violation), and skip subjective claims like "best" or "cheap."
Backend keywords contribute to whether a listing is indexed for a search term but are a weak ranking signal compared with title placement, sales velocity, and conversion. Treat them as coverage for the long tail, not a ranking lever.
A stainless steel water bottle listing whose title says "Insulated Water Bottle" adds backend terms like "flask thermos tumbler hydro canteen 32oz leakproof" to capture searches it would otherwise miss — staying under the 250-byte limit.