Does punctuation affect Amazon backend keywords?
Punctuation in Amazon's backend Search Terms field has real consequences for how your keywords are indexed and how efficiently you use your 250-byte allowance. Most punctuation characters are either stripped out by Amazon's indexer or treated as spaces, meaning they occupy byte space without contributing to indexation. Understanding which characters to avoid and which behave predictably allows you to build a cleaner, more byte-efficient backend keyword list and avoid common formatting mistakes that reduce the effective coverage of your Search Terms field. Amazon's indexer processes the Search Terms field as a sequence of tokens separated by whitespace. When it encounters punctuation, its behaviour depends on the character type. Commas are treated as token separators, effectively functioning as spaces, but they consume one byte each. Using a comma instead of a space between keywords does not harm indexation but it wastes a byte per comma. A Search Terms field with 20 commas between keywords is 20 bytes shorter than it could be if spaces were used instead. Hyphens are treated as separators in a way that also indexes compound forms: as covered in the hyphens FAQ, 'non-stick' indexes both 'non-stick' and 'non stick'. This makes hyphens the one punctuation type that carries genuine indexation value for compound product terms. Quotation marks, parentheses, brackets, semicolons, exclamation marks, at signs and most other special characters are stripped or ignored by the indexer: they do not enhance indexation and they consume bytes. Underscores have inconsistent behaviour and should be avoided. The most frequent punctuation mistake is using commas to separate keywords, often because sellers copy and paste keyword lists formatted with commas from research tools or spreadsheets. A Search Terms field formatted as 'bamboo, cutting board, wood, kitchen, eco, dishwasher safe, end grain' contains seven commas, each consuming one byte. Replacing those commas with spaces recovers seven bytes with no loss of indexation: 'bamboo cutting board wood kitchen eco dishwasher safe end grain' is identical in indexation effect but seven bytes shorter. Another common mistake is wrapping keyword phrases in quotation marks, often under the mistaken impression that quotes create phrase-match indexation in the same way they do in Google Ads. Amazon's backend indexer does not use quotation marks as phrase-match operators. A quoted phrase 'bamboo cutting board' is processed identically to the unquoted sequence bamboo cutting board, but the two quote characters consume two bytes. Remove all quotation marks from your Search Terms field. Numbers are indexed normally by Amazon and behave the same as words. '12 inch', '2 pack' and '500ml' are all valid keyword fragments that Amazon indexes without modification. There is no need to spell out numbers as words for indexation purposes: '2 pack' and 'two pack' are indexed separately and, where both are common search terms, you may want to include both variants explicitly. Special characters including trademark symbols, copyright symbols, degree signs and currency symbols are stripped or ignored by Amazon's indexer. They also typically consume more than one byte each in UTF-8 encoding, making them doubly wasteful in a byte-limited field. Do not include trademark or registered symbols in your backend Search Terms field: these are appropriate in your visible listing content where branding is relevant, but they have no indexation function in the backend field.
Most punctuation in Amazon backend keywords is ignored or treated as a space, but some characters waste bytes. Learn which punctuation to avoid in Search Terms.