App Store Optimization (ASO): A Practical Guide

App Store Optimization (ASO) is the work of getting an app to rank in App Store and Google Play search and getting the people who see it to install. Apple says 70% of App Store visitors use search to find apps and almost 65% of downloads happen directly after a search, so for most apps this is the largest source of installs and the only one that costs nothing per download.

On iOS you get 160 characters to tell Apple what your app is about: 30 in the name, 30 in the subtitle and 100 in a hidden keyword field. Most of ASO is spending those characters well, then making sure the icon, screenshots and rating convert the people you reach. Here is how I would do it, with the rules Apple and Google actually publish and the popular advice they do not back.

What decides your ranking

Apple's search documentation names the inputs: "text relevance (matches for your app's title, subtitle, keywords, and primary category), as well as user behavior (downloads, ratings and reviews, and more)". Read that as two gates. The words in those four places decide whether you can appear for a search at all. Downloads and ratings decide how high.

Google Play has no keyword field. It reads the title (30 characters), the short description (80) and the full description (4,000), and ranks on what Google calls "a combination of ratings, reviews, downloads, and other factors".

The consequence for a new app: you cannot outrank established apps on downloads, so you win on relevance for narrower searches first.

Write the name and subtitle like the top apps do

Look at what the leaders put in their 60 visible characters on the US App Store today:

The pattern is brand, then the words people search. None of them spends characters on a slogan. Calm can afford a one-word name because people search for it by name. You cannot yet, so use the format "Brand: main keyword" and put your second most valuable terms in the subtitle.

Two rules for these fields. Do not repeat a word between name and subtitle, because Apple already indexes both. And keep it readable. "Budget Planner Expense Tracker Money" ranks no better than a name a person would say out loud, and it converts worse.

Fill the keyword field properly

The 100-character keyword field is where most apps waste space. Take a habit tracker. This is what a typical first attempt looks like, 92 characters, most of them thrown away:

habit tracker,habits,habit app,daily habits,best habit tracker,routine,the tracker app,goals

"Habit" and "tracker" are already in the name. "Habits" is a plural, which Apple treats as a duplicate. "App", "best" and "the" add nothing. Here is the same app done properly:

The first version added three useful words to what was already in the name. This one adds sixteen. The rules behind it all come from Apple:

• Commas between terms, no spaces after them.
• Nothing that is already in the name, subtitle or category.
• Singular or plural, never both.
• No "app", "free", "best" or "the".
• No competitor names or trademarks. Apple calls improper keywords "a common reason for App Store rejections".

Use single words where you can. In practice the App Store matches searches against words from all three fields in combination, so "habit" in the name plus "reminder" in the keyword field can put you in results for "habit reminder". Apple does not document that behavior, but it is the reason its own guidance tells you not to repeat words. How to choose which words deserve a place is covered step by step in the guide to App Store keyword research.

Go after searches you can win

Apple's advice here is blunt: popular terms "may drive a lot of traffic, but are highly competitive, especially if you are a newer or smaller app", while less common terms "are less competitive". Being first for "sobriety counter" is worth more than being 140th for "health".

My rule for a new app: pick terms where the apps currently in the top five have ratings in the hundreds or low thousands, not the millions. Rank there first. As downloads and ratings build, swap in broader terms one release at a time, and drop any keyword you have not moved on after two or three versions.

Find keywords with a small ad campaign

The most reliable keyword data comes from Apple, and you get it by advertising. Apple's own campaign structure guide recommends four campaigns: brand, category, competitor and discovery. The discovery campaign is the one that matters for ASO.

Set up one ad group with Search Match on and no keywords. Apple will show your ad for searches it considers relevant, and the search terms report then tells you which real queries people tapped and installed from. A few dollars a day for two weeks is usually enough to see a pattern. Take the terms that converted, check you are not already targeting them, and put them into your name, subtitle or keyword field in the next release.

Screenshots: design for search results, not the product page

People can install straight from search results without opening your page. What they see there is the icon, the name, the subtitle, the rating and, in Apple's words, "the first one to three" screenshots, depending on orientation. Portrait gets you three. Landscape gets you one.

• Use portrait, and treat the first three as a single ad read left to right.
• Put a caption of three to five large words on each, stating a result the user gets. "Never miss a dose" beats "Smart reminders".
• Show the app doing its main job in the first screenshot. No splash screen, no logo, no "Welcome".
• Check the set at thumbnail size on a phone. If you cannot read the caption there, nobody can.

Then test it. Apple's product page optimization runs up to three alternative versions of your icon, screenshots and preview video against the original for up to 90 days. Google Play has store listing experiments. Test the first screenshot before anything else, and change one element per test.

For a sense of scale: AppTweak measured an average conversion rate from product page view to download of 8.56% on the US App Store and 16.15% on US Google Play in 2025, with category averages ranging from about 5% for trivia games to over 50% for food and drink. Compare yourself with your own category only.

Ratings

Your star rating sits beside the icon in every search result, and Apple states that ratings and reviews "can influence how your app ranks in App Store search". So it works on both gates.

Ask for ratings in the app, using the system prompt, right after the user has succeeded at something: finished a workout, hit a streak, exported a file. Apple allows the prompt to appear up to three times in 365 days, so do not waste one on first launch. Reply to every negative review of the current version. Apple notifies the reviewer, who can then change the rating, and a fixed bug with a polite reply is how one-star reviews become four.

Custom product pages

You can publish up to 70 custom product pages on the App Store, each with its own screenshots. Since October 2025 you can also assign keywords to them, and the custom page then appears in search for those keywords in place of your default one.

This is the most underused feature in ASO right now. If your habit tracker ranks for "quit smoking", build a page whose screenshots are all about quitting smoking and assign that keyword to it. The keywords have to come from your approved keyword field, and each keyword can belong to only one page. Google Play's custom store listings can be targeted by search keyword in the same way.

Localization, including the one most people miss

Every language version of your listing has its own name, subtitle and keyword field. Translating them gives you another 160 characters in each market, and Apple says localized keywords are searchable in every country where the App Store supports that language.

Check Apple's table of storefront languages before you decide which to add. The US store, for example, supports Spanish (Mexico) as well as English. An app that fills in a Spanish (Mexico) listing gets a second set of indexed fields in its biggest market. Many ASO practitioners use that second keyword field for more English terms. Apple does not describe that use, so treat it as a tactic that works today, not a guarantee.

Google Play is a different job

• Put your main keyword in the 30-character title and the next two or three in the 80-character short description.
• Write the full description as real sentences that use your terms naturally, with the most important ones in the first few lines. Google's own example of what gets an app suspended is a string of comma-separated variations of "car racing".
• Fix crashes before you touch the text. Google says apps that exceed its bad behavior thresholds for crashes and freezes are "likely to be less discoverable".
• Choose up to five tags carefully. Google uses them, with the category, to help people find the app.

What to ignore

• Keywords in the iOS description. Apple does not list it as a search field and tells developers not to add "unnecessary keywords" to it. Write it for people.
• Keyword density targets for Google Play. The "2 to 3 percent" figure comes from tool vendors. Google publishes no number.
• Stuffing keywords into screenshot captions. Appfigures reported in 2025 that Apple had started reading captions as keywords. A test by ConsultMyApp of 64 caption phrases found that almost every ranking was explained by ordinary metadata. Write captions that sell.
• Changing category to find less competition. The category is one of Apple's four text signals, so the wrong one costs relevance. The guide to App Store categories covers when a change is justified.

How to measure it

In App Store Connect, open App Analytics and filter by source "App Store search". Track impressions, product page views, downloads and conversion rate. Two things to know: that source includes installs from search ads, and Apple gives you no organic report by keyword, so for keyword-level ranks you need a tracker or your Apple Ads search terms.

Read the numbers together. Impressions up and conversion down means you now rank for terms that do not fit the app. Impressions flat and conversion up means the new screenshots worked. Keep a dated log of every metadata change, or you will never connect a ranking move to its cause.

The routine

1. Every release: replace the keywords that have not moved, and add the converting terms from your discovery campaign.
2. Always have one listing test running, on the first screenshot or the icon.
3. Weekly: reply to new negative reviews.
4. Monthly: check conversion rate by country and localize where traffic is growing.
5. Quarterly: look at what the top five apps for your main keyword changed in their names, subtitles and screenshots.

ASO is one channel. How it fits with paid acquisition, retention and revenue is in the guide to app marketing.

FAQs

What is ASO?

ASO stands for App Store Optimization. It is the practice of improving how an app ranks in App Store and Google Play search, and the share of people who install it after seeing the listing.

What is the difference between ASO and SEO?

SEO ranks web pages in search engines such as Google. ASO ranks apps inside the app stores. Stores look at a few short metadata fields plus downloads and ratings, while web search looks at page content and links. On the App Store you have 160 indexed characters to work with.

Is App Store Optimization important?

Yes. Apple says almost 65% of downloads happen directly after a search, and those installs cost nothing per download. A listing that converts better also makes every paid campaign cheaper, because more of the people you pay to reach install.

How much does App Store Optimization cost?

It can cost only your time. The store consoles and both stores' testing features are free, and a small Apple Ads discovery campaign for keyword data can run on a few dollars a day. Paid ASO tools add rank tracking, and agencies charge a monthly fee to run the process.

Does the app description affect ranking?

On Google Play, yes. Google reads the full description. On the App Store, Apple names the title, subtitle, keyword field and primary category as the text it matches, and not the description.

How long does ASO take to work?

Metadata changes go live when a new version is approved, and rankings keep moving for a few weeks after. Judge a keyword change after two or three weeks, and a listing test when Apple or Google reports a confident result.

Sources

• Apple Developer: Search, product page and custom product pages
• Apple Ads: search statistics and campaign structure
• Google Play Console Help: store listing fields, discovery and ranking and custom store listings
• AppTweak: average app conversion rate per category, 2025
• App names and subtitles are from the US App Store listings on October 5, 2026.