How big is the iOS keyword field?

The App Store keyword field holds exactly 100 characters of comma-separated terms. It is hidden from users and used only for search matching, so packing it efficiently directly affects which searches your app can rank for.

Why remove words that are in my app title?

Apple already indexes every word in your app name and subtitle for search, so repeating them in the keyword field wastes precious bytes. This builder strips title words so the 100 characters go entirely to new terms.

Should I use spaces in the keyword field?

No. Apple ignores spaces after commas but they still consume characters, so the builder joins terms with commas and no spaces. It also splits phrases into single tokens because Apple matches across the comma list to form multi-word searches automatically.

Can I use competitor names as keywords?

You can include generic competitor app names, and many developers do, but avoid trademarked terms you have no right to and Apple may reject. The builder includes them as candidates so you can decide which to keep.

What happens to terms that don't fit?

Terms that overflow the 100-character limit are listed separately as lower-priority so you can swap them in for weaker keywords. Nothing is silently lost — you see exactly what fit and what didn't.

What is the App Store Keyword Field Builder?

Takes your app title, features, and competitors and outputs a comma-separated 100-character iOS App Store keyword string, automatically dropping words already in your title, stop words, and duplicates so every byte counts toward search ranking. It runs free in your browser on Gera Tools, with nothing uploaded.

App Store Keyword Field Builder

Name: App Store Keyword Field Builder
Creator: Gera Tools
License: https://creativecommons.org/licenses/by/4.0/

Make every one of your 100 characters earn its place

The iOS keyword field is one of the highest-leverage ASO inputs and one of the most commonly wasted, because developers fill it with words Apple already indexes from the app name. This builder strips those out, removes duplicates and stop words, splits phrases into the single tokens Apple actually matches on, and greedily packs the highest-value terms into exactly 100 characters.

How it works

You enter your app title and subtitle, plus features, competitor names, and extra related terms. Apple already indexes title and subtitle words for search, so the builder excludes any single-word term that appears there. It also drops common stop words like the, app, and free, which Apple auto-indexes, and removes duplicates. Multi-word phrases are split into unique single tokens because the App Store recombines comma-separated keywords into multi-word searches on its own — so storing photo and editor separately also covers “photo editor”. Finally it fills the field greedily with commas and no spaces, since spaces consume bytes without helping matching, and shows you both what fit and what overflowed.

What the App Store keyword field actually is

The 100-character keyword field is completely hidden from users — it does not appear on your store listing, in search results, or in any public-facing surface. It is used exclusively by Apple’s search algorithm to determine which search queries your app is eligible to rank for. This makes it pure algorithmic signal: every character should carry new ranking potential.

Apple automatically combines individual tokens across your title, subtitle, and keyword field to form multi-word searches. This means if your title contains “photo” and your keyword field contains “editor”, your app is eligible to rank for “photo editor” without either full phrase appearing anywhere. The builder exploits this by splitting any phrase you enter into its component tokens.

Practical example

App title: PhotoFlow: Photo Editor Subtitle: Filters & Collage Maker Features you enter: retouching, color grading, batch edit, camera, portrait, background remover Competitor terms: vsco, lightroom, snapseed

The builder removes “photo” (in title), “editor” (in title), “filters” (in subtitle), “maker” (in subtitle), and “collage” (in subtitle), then packs the unique remaining tokens:

retouching,color,grading,batch,edit,camera,portrait,background,remover,vsco,lightroom,snapseed

That is 92 characters — under the 100-character limit, with space for 8 more characters if you have additional terms.

Tips for the best results

Put your highest-value terms first. When terms overflow the 100-character limit, the builder packs them in order — terms at the start have priority.
Think about the searches your users actually type, not the categories you belong to. Someone looking for a “morning routine tracker” types those words; Apple handles combining them.
Review the overflow list at each update cycle. Rotate terms based on which search queries are converting in App Analytics, not just which sound relevant.
Update at every new release. Your keyword field can be changed with each app update and takes effect after the update is approved — use this as a regular optimisation loop.