How App Store keyword indexing actually works

Apple indexes your app for search from four sources, in descending weight:

  1. App name (30 characters) — highest weight. Every word here is indexed and carries the most ranking signal.
  2. Subtitle (30 characters) — second highest weight, also visible to users in search results.
  3. Keyword field (100 characters) — indexed but not visible to users. Adds coverage for terms not in your name or subtitle.
  4. In-app purchase names — Apple indexes these too, which is a free source of additional keyword coverage if you have IAPs.

The description is not indexed for App Store Search. Unlike Google Play, stuffing keywords into your iOS description does nothing for search ranking. Google Play indexes the full description — if you're building for both platforms, your keyword strategy differs per store.

The practical implication: your 100-character keyword field should contain only terms that don't already appear in your app name or subtitle. Repeating words across fields wastes space — Apple ignores duplicates.

Apple's rules for the keyword field

Apple enforces several rules that aren't always obvious:

The 100-character budget: count characters including commas. habit,tracker,streak,journal,morning,routine,reminder,productivity is 63 characters — you have 37 left. Use a character counter while building your list; App Store Connect will reject the field silently (or truncate) if you go over.

Where to find keywords worth targeting

1. App Store search suggestions

Open the App Store on your phone, tap the search bar, and start typing terms related to your app. The autocomplete suggestions are Apple's direct signal of what users are actually searching. Every suggestion represents real search volume. Screenshot these as you type — they're your highest-confidence keyword source because they come straight from Apple's data.

2. Competitor metadata

Your top 3–5 direct competitors have already done keyword research. You can reverse-engineer their strategy by reading their app names, subtitles, and (on Google Play) their descriptions. Tools like AppFollow, AppTweak, and Sensor Tower can show you competitor keyword rankings directly. Free alternatives: just read their listings carefully and note every term they use in name and subtitle positions.

3. Category charts

Browse the Top Charts in your app's category. Look at the app names and subtitles of the top 20 apps — these are the terms that appear most consistently among high-ranking apps in your space. Any term that appears in multiple top-ranking listings is worth investigating.

4. Related searches and "Customers Also Bought"

On a competitor's product page, scroll down to the "You Might Also Like" section. Apple surfaces apps with overlapping keyword coverage here — it tells you which keyword clusters your competitor is ranking in. Those clusters are candidates for your keyword field.

5. Google Keyword Planner (for intent signal, not volume)

App Store search volume data isn't publicly available — the numbers in ASO tools are estimates, not actual Apple data. Google Keyword Planner gives you search volume for the web equivalent of your keywords, which is a reasonable proxy for relative intent (terms with 10x the web volume often have 10x the App Store search volume too). Use it to rank your candidates by likely demand, not as an absolute measure.

How to prioritize your 100 characters

Once you have a list of candidates, you need to fit them into 100 characters. The prioritization logic:

Relevance first

A keyword is only valuable if users who search it would install your app. High-volume irrelevant terms give you impressions from the wrong audience — low conversion rate, which damages your ranking for those terms over time. Relevance beats volume.

Prefer shorter individual keywords over long phrases

Apple recombines your individual keywords into phrases automatically. If you put habit,tracker,daily,streak in your field, Apple will rank you for "habit tracker", "daily habit", "streak tracker", "habit streak", and more — all from 4 short words that together use only 26 characters. Explicitly writing habit tracker,daily streak uses more space and gives you fewer combinations.

Avoid high-competition terms you can't rank for yet

A new app with no ratings targeting "productivity app" — a term dominated by Notion, Todoist, and Things — won't rank for it. Better to own a more specific term ("focus timer", "pomodoro tracker") where the competition is thinner and the searcher intent is more specific. As your app grows ratings and install velocity, you can gradually target broader terms in subsequent keyword updates.

Use numbers and abbreviations to save space

App Store indexes numbers. 7day and 7-day and "7 day" are all searched. Single characters like ai index fine. Short forms save space: mgmt for management, tracker covers "track" and "tracking", reminder covers "remind" and "reminders".

When to update your keywords

Keyword changes take effect with your next app version submission — you can't update the keyword field independently without submitting a binary. The promotional text and description can be changed without review, but the keyword field cannot.

Update your keywords when:

Don't change keywords reactively after every small impression dip — rankings take 1–2 weeks to stabilize after a keyword change, and churning the keyword field prevents you from ever building stable ranking for any term.

Keywords vs screenshots: which moves downloads more

Keywords determine whether your app appears in search results. Screenshots determine whether users who see your listing tap through and install. Both matter, but they operate at different stages of the funnel.

A common mistake is optimizing keywords while ignoring screenshots. You can rank #3 for "habit tracker" and still have a low conversion rate if your first screenshot doesn't communicate a clear value proposition in the search result crop. The keyword gets you the impression; the screenshot converts it.

Once your keyword coverage is solid, the highest-ROI next step is usually improving your first screenshot — particularly the caption placement and copy. ezscreenshots makes it fast to create variants for A/B testing via Product Page Optimization. For what the top-converting screenshots actually look like, see the App Store screenshot template guide.

The keyword field isn't the whole picture

The keyword field is the easiest lever to pull, but it's not where most of your keyword budget lives. Your app name and subtitle combined give you 60 characters at the highest index weight. If those aren't keyword-optimized — if they're clever marketing names rather than descriptive terms — no amount of keyword field tuning will compensate.

For the complete ASO strategy covering name, subtitle, keyword field, screenshots, and ratings together, see the App Store optimization strategy guide.

Keywords get you the impression. Screenshots close the install.

Once your keyword coverage is in place, the first screenshot is the next conversion lever. ezscreenshots exports outcome-focused, correctly sized screenshots in minutes. Free, no account needed.

Try ezscreenshots →

Summary