What is app store optimization (ASO)?

ASO is the practice of improving an app's store listing so it ranks higher in search and converts more visitors into installs. The biggest levers are the title, subtitle, keyword field, and the first lines of the description — exactly what this builder structures.

What are the App Store character limits?

On the Apple App Store the title allows up to 30 characters, the subtitle up to 30, and there is a separate 100-character keyword field. The description can run to 4,000 characters. This builder counts each field live so you stay within the limits.

How are Google Play limits different?

Google Play gives a 30-character title, an 80-character short description, and a 4,000-character full description, and it has no separate keyword field — instead it indexes the descriptions. The builder switches counters and structure when you pick Google Play.

Where do keywords matter most in a listing?

On iOS, the title, subtitle, and the dedicated keyword field carry the most weight, so put your strongest terms there. On Google Play, repeat important keywords naturally across the short and full descriptions since those are what Google indexes.

How important are the first lines of the description?

Very. Most users only see the first two or three lines before tapping 'more', so lead with your strongest benefit and a clear call to action. Both stores also weigh early text more heavily, making those opening lines double duty for ranking and conversion.

App Store Listing Copy Builder

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A listing built for ranking and installs

Your app store listing is both an ad and a search result. The title, subtitle, and keyword field decide whether you rank for the searches users type, while the description and first visible lines decide whether they tap install. This builder assembles a complete, platform-correct listing — title, subtitle, short and long descriptions, and a keyword field — with live character counters so every field stays within Apple or Google’s limits.

How it works

You enter your app name, its one-line value, key features, and target keywords. The tool then:

Builds a title and subtitle that lead with your value and weave in a keyword.
Generates a short description (the promotional line) and a benefit-led long description with a feature list and call to action.
Packs your keywords into a comma-separated keyword field for iOS, trimmed to 100 characters.
Switches character limits and field structure when you toggle between App Store and Google Play.

Every field shows a live counter that turns to a warning state if you exceed the store’s limit. All of this runs in your browser.

Tips for a stronger listing

Put your single most-searched keyword in the title, since it carries the most ranking weight on both stores. Use the subtitle (iOS) or short description (Android) to add a second benefit and a second keyword rather than repeating the title. Front-load the description with the benefit and a call to action — most users never tap “more.” For the iOS keyword field, drop spaces after commas to fit more terms, never repeat words already in the title, and avoid plurals the store already handles for you.