How the iOS keywords field actually works
A hundred characters is not a hundred keywords, and most of the field's real capacity is lost to habits that don't help: repeated words, extra spaces, and terms already covered by the title.
Apple tokenizes the keywords field into individual words and recombines them with your title and subtitle; most of the waste in a keywords field is duplicated words, not bad word choices.
Apple's keywords field, set in App Store Connect, is 100 characters, comma-separated, invisible to users, and one of the only pieces of ASO metadata that's pure keyword surface with no persuasion job to do. Getting the mechanics wrong wastes real search visibility.
It's tokenized, not matched as phrases
Apple's search index doesn't just match your keywords field as literal phrases. It breaks the field, your app's title and your subtitle into individual word tokens, then recombines them to match a much larger set of search terms than what's literally typed in any one field. That's why a word that already appears in your title or subtitle is wasted if you repeat it in the keywords field; you already own that token.
Common ways the 100 characters get wasted
- Repeating a word already in the title or subtitle (each occupies its own field, so the token is already covered).
- Using spaces where a comma would let you drop a character (“photo editor” costs a literal space; “photo,editor” tokenizes the same words for one fewer character).
- Plurals and singulars of the same word (Apple's matching handles common plurals; keeping both wastes characters more often than it helps).
- Your own brand name, if it isn't also something people search before they know your app exists.
A better way to spend the space
Once title and subtitle tokens are accounted for, prioritize: keywords with meaningful search volume that aren't yet covered anywhere in your metadata, competitor brand or feature terms where relevant (subject to Apple's trademark guidelines), and category or use-case terms a searcher would type before they know your app's name.
How often to revisit it
Not on a fixed schedule. Revisit the field when you add a feature that introduces new relevant search terms, when review mining (see our review-mining guide) surfaces a phrase users actually use that you're not covering, or when a tracked keyword is clearly underperforming and a swap is worth testing.
The keywords field is one of the criteria we score every tool on in our ASO tool ranking.
Frequently asked questions
Is Apple's 100-character keywords field matched as exact phrases?+
No. Apple tokenizes it into individual words and recombines them with your title and subtitle to match a broader set of search terms than any single field taken literally.
Should I repeat words from my title in the keywords field?+
No, that wastes character space. If a word already appears in your title or subtitle, you already own that search token; use the keywords field's characters for terms you haven't covered elsewhere.
Do commas or spaces matter in the keywords field?+
Yes, commas are more character-efficient than spaces between multi-word phrases, since a comma separates terms without costing a literal space character.
How often should I update my keywords field?+
When something specific changes: a new feature, evidence a tracked keyword underperforms, or new phrasing found by mining your own reviews. Changing it on a fixed calendar regardless of evidence just spends review cycles.