App Store keywords (ASO): how to pick and test them

The fields that count for search

Three fields in each localization of your App Store listing are used for search:

• App name: up to 30 characters, visible to everyone, the strongest signal
• Subtitle: up to 30 characters, shown below the name
• Keywords: up to 100 characters, not visible on the store, separated by commas

Rules for the keyword field

Separate keywords with commas and leave out the spaces after them. Every space costs one of your 100 characters. Spaces inside a keyword are fine, but you can usually split phrases into single words, because the App Store combines words from your name, subtitle and keywords into search phrases.

Don’t repeat words that are already in your name or subtitle. They are already indexed, so repeating them only wastes space. The same goes for your company name and the name of your category in many cases.

Don’t use trademarks, competitor app names or celebrity names you have no rights to. App Review rejects this, and it rarely brings users who stay.

For languages with special characters, check the counter in App Store Connect: the limit can be reached sooner than the visible character count suggests.

Keywords, name and subtitle belong to an app version, so you can only change them when you submit a new version.

Every localization has its own fields

Each language you add in App Store Connect has its own name, subtitle and keyword field. Even if you only translate a few screens of your app, a well-written German listing will do far more for searches in German than English keywords ever could.

Some storefronts also take additional localizations into account. The US store, for example, is widely reported to index the Spanish (Mexico) localization in addition to English (US). Many developers use this to add more English keywords in a second localization. Apple publishes which languages are available in which storefronts, but not exactly how they are weighted, so treat this as a bonus, not as a guarantee, and keep the content of every localization meaningful for people who actually read it.

How to pick keywords

Good keywords combine three things: people search for them, your app is a genuinely good answer, and the competition is beatable.

• Start with how your users describe the problem, not with how you describe your app. Reviews and support emails are a great source.
• Search the App Store yourself and look at the top results. If they all are huge, well-known apps, a smaller app will struggle there.
• Prefer specific phrases over broad single words. A long-tail search with less volume that you can rank in the top results for usually brings more downloads than a broad term where you sit far down the list.
• Use the App Store search suggestions as a rough signal of what people type.
• Put your most important term into the name or subtitle, then fill the keyword field with the rest.

How to test and track

Change one thing at a time and give it time. After a new version goes live, rankings can move for several days before they settle, so compare a week before and after rather than the next morning.

Track rankings for your keywords in each country that matters, plus your impressions and conversion rate in App Analytics. A keyword is only worth keeping if it brings impressions that convert into downloads. If a term ranks well but brings nothing, replace it.

Product page optimization in App Store Connect lets you test icons, screenshots and app previews against each other. It doesn’t test your name, subtitle or keywords; for those, before-and-after comparisons are the practical method.

Tracking keywords with Connect Insights

Connect Insights shows keyword rankings for your apps in many countries, found automatically, together with a visibility score per app and its history and your position in the top charts. ASO for your most important app is free.

With Connect Insights Pro you get ASO for every app and concrete suggestions for the title, subtitle and keyword field of every localization, so you can see where characters are wasted and which terms are worth trying next.