Listing content
What is Backend search terms?
Backend search terms are a hidden keyword field Amazon indexes but shoppers never see. The limit is 250 bytes, and exceeding it can void the entire field rather than truncating the overflow.
Why it matters
It is the cheapest ranking real estate on Amazon and the most commonly wasted. Most listings either leave it empty, repeat the title into it, or blow the byte limit and lose all of it silently.
The limit is bytes, not characters. Standard Latin characters are one byte, but accented and non-Latin characters cost two or three — so the effective budget on amazon.de or amazon.co.jp is much smaller than it looks.
Do not repeat words already in your title or bullets, since Amazon indexes a term once. Skip commas, which consume bytes without separating anything. Never include competitor brands, ASINs or subjective claims — all are policy violations.