How to Fill the App Store Keyword Field (100 Characters)

The App Store keyword field is a hidden, comma-separated list of up to 100 bytes per localization that Apple uses for search. To use it well, list single words separated by commas with no spaces, skip anything already in your app name, subtitle or developer name, and spend the space on relevant terms people actually search for. Google Play has no equivalent field — this guide is App Store only.

How Apple indexes keywords

Apple builds your search footprint from a few fields, per localization:

• Words combine across fields. If “habit” is in your name and “journal” in your keywords, you can rank for “habit journal”. You don’t need phrases in the keyword field.
• Combination works within one localization. Words from your English (U.S.) metadata and your Spanish (Mexico) metadata are commonly reported not to combine into one phrase, even though both can be indexed in the US storefront.
• Placement matters. A word in the name is generally weighted more than the same word in the keyword field, so put your single most important term in the name or subtitle.
• In-app purchase names count too. Promoted in-app purchases and subscriptions with descriptive display names (“Pro Habit Insights”) can surface in search, so name them for what they do rather than “Tier 2”.
• The description doesn’t help App Store ranking. Write it for people already on your page; put search terms in the indexed fields instead.

Formatting rules

• Commas, no spaces: habit,streak,journal — not habit, streak, journal.
• Single words over phrases: water,reminder covers “water reminder”, “reminder water” and each word alone. A phrase is only useful if it’s a fixed term people search as a unit.
• One form per word: Apple usually matches singular and plural forms, so pick one.
• Bytes, not characters: letters, digits and commas are 1 byte; accented letters typically 2; Chinese, Japanese, Korean and Thai characters typically 3.
• Lowercase is fine: search isn’t case-sensitive.
• No special characters or hashtags; they don’t help matching.

What not to put in the field

Choosing keywords

1. List candidates from your features, user problems and the words in your reviews. Use App Store autocomplete to see what people type.
2. Check popularity with Apple Ads (formerly Apple Search Ads), which shows search popularity for terms when you build a campaign.
3. Check competition by searching each term. A word dominated by giant apps is hard to rank for; a more specific one may convert better.
4. Check relevance: would someone typing this be happy to find your app? Irrelevant traffic doesn’t install.
5. Prioritize: the most important term goes in the name or subtitle, the next tier in the keyword field, and everything else is a candidate for a later version or another localization.

Worked example: a habit tracker

A hypothetical app with name “Ripple: Habit Tracker” (21 characters) and subtitle “Daily Goals & Routine Planner” (29 characters).

Before — 106 bytes (too long to save)

habit tracker, habit, tracker, daily routine, goals, best habit app, free, streak, planner, todo, reminder

• Spaces after every comma waste 10 bytes.
• “habit”, “tracker”, “daily”, “routine”, “goals” and “planner” are already in the name or subtitle.
• “best”, “app” and “free” add nothing and conflict with Apple’s guidelines.
• Phrases like “habit tracker” repeat words that combine automatically.

After — 100 bytes, 15 new words

streak,reminder,todo,checklist,journal,mood,water,sleep,meditate,self,care,discipline,focus,quit,gym

“self” and “care” are entered as separate words so they can also combine with other terms; “goal” is left out because “Goals” is in the subtitle. Several of the new combinations (“sleep tracker”, “gym planner”) only work because Apple combines words from the name and subtitle with the keyword field.

Extra keyword space from localizations

Apple’s App Store localizations reference lists, for each storefront, a default language and additional supported languages. ASO practitioners commonly report that metadata in those additional localizations is also indexed for search in that storefront — so each one adds another name, subtitle and 100-byte keyword field.

• Keep it honest. A Spanish (Mexico) localization is shown to real Spanish-speaking users in the US and Mexico. Fill it with genuine Spanish metadata and screenshots — if you put English keywords there, keep the visible fields sensible.
• Words don’t combine across localizations (commonly reported), so put full phrases’ worth of words in one locale.
• Check what each locale displays before you change it; the listing preview shows name and subtitle as they appear in search.

For which markets to localize and the locale codes, see localizing App Store & Google Play screenshots.

Updating and measuring

• Keywords change only with a new version. Prepare them while you prepare the build; you can’t edit them after the version is approved.
• Change a few at a time — swap three to five low performers per release, keep the rest stable, and record the date.
• Measure with App Store Connect Analytics: watch impressions and downloads from the App Store Search source, and compare equal periods before and after the release.
• Allow time. Rankings often take days to a few weeks to settle after a change.

Optimizing the field with our tools

Paste your name, subtitle and keyword list into the keyword optimizer: it removes spaces and duplicates, flags words already in your name or subtitle, and shows the byte count. The character counter checks every other field. In the editor, the metadata panel keeps keywords per locale, can draft and translate them with AI using your own key, and exports them as fastlane keywords.txt files. For the bigger picture, read the ASO guide and the full character limits list.