Amazon's backend search term field has a 250-byte limit (not characters). This counter measures bytes precisely.
Amazon counts bytes, not characters. ASCII characters = 1 byte each. Chinese, Japanese, Korean, and emoji characters use 2–4 bytes each. Separate keywords with spaces (no commas needed). Do not repeat keywords already in your title or bullets.
Paste your backend search terms
Copy your keyword list from your keyword research tool and paste it into the input field.
Check the byte count
The tool counts bytes, not characters. ASCII characters (standard English) are 1 byte each; special or accented characters may be 2+ bytes.
Stay under 250 bytes
Amazon's backend search term field accepts a maximum of 250 bytes. The counter turns red if you exceed this limit.
Remove duplicates and irrelevant terms
Use the space wisely — avoid repeating keywords already in your title or bullets, as Amazon indexes those automatically.
Amazon uses byte counting because its system is UTF-8 encoded. Standard English characters are 1 byte each, but special characters (é, ü, ™) can be 2–4 bytes. This matters if you sell in non-English markets.
Amazon allows up to 250 bytes per search term field. Listings that exceed this limit may not save correctly, and Amazon may truncate your keywords, reducing your listing's discoverability.
No. Amazon recommends separating keywords with spaces, not commas. Commas are counted as characters and waste your byte limit. Amazon's algorithm treats spaces as separators.
No need — Amazon automatically indexes words in your title, bullets, and description. Use your backend search term space for keywords that don't appear in your visible listing text to maximize coverage.