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What is App Store Optimization and Why is ASO Important?

Alexandra De Clerck by ,  Head of Marketing at AppTweak Start ASO

Are you new to App Store Optimization? In this guide, you’ll find everything you need to know about ASO, app store ranking signals, how ASO is different for the App Store and Google Play, and how to get started with ASO.

What is App Store Optimization (ASO)?

ASO Definition

App Store Optimization (ASO) is the process of improving an app’s visibility in the app stores with the objective of increasing organic app downloads. Apps are more visible when they rank highly on a wide variety of search terms, maintain a high position in the top charts, or get featured on the store.

Keyword Optimization vs Conversion Rate Optimization

ASO focuses mostly on two pillars: keyword optimization and conversion rate optimization.

  • Keyword Optimization: Keyword optimization involves researching, analyzing, and selecting the right keywords to include in an app’s title, subtitle, keyword field, and long description.
  • Conversion Rate Optimization: Conversion rate optimization is the systematic process of adjusting the textual and visual elements of an app’s product page to ensure that a higher percentage of users download the app after seeing it.

These two pillars work closely together – a solid keyword optimization strategy will result in higher rankings, while great conversion rate optimization procedures will make sure that increased visibility leads to more app downloads.

The Basics of ASO

There are a lot of factors that can impact your app’s visibility and organic downloads (more on this later) and, as a result, an ASO expert’s job is very diverse. Depending on a company’s priorities, goals, and KPIs, ASO can consist of:

  • Executing keyword research to optimize metadata with the most searched for keywords.
  • Optimizing creative assets such as icons, screenshots, and videos to encourage more users to download your app.
  • Localizing the app’s product page to foreign languages worldwide.
  • Implementing a review strategy to ensure a steady stream of positive reviews.
  • Increasing the app’s visibility in editorial content, featured stories, or “Similar Apps” placements.
  • Monitoring app store changes and competitor updates to maintain visibility.


App Store Optimization, or ASO, is often referred to as mobile SEO or SEO for apps. This analogy comes in pretty handy when understanding the overall principle of ASO. But the app stores and the web are two very different ecosystems, hence there are quite some differences between ASO and SEO.

  1. Search Intent: Search queries in the app stores are generally shorter than on the web. People tend to search for specific apps by their brand name or are looking for new apps that can serve an exact need. When searching the web, people often seek answers to specific questions or they make queries about buying a certain product or service. Therefore, search queries tend to be longer.
  2. Keywords: In the app stores, keyword optimization is limited to the app title, subtitle, and keyword field or long description. Therefore, app marketers need to carefully select a handful of relevant keywords to increase their visibility. On the web, conversely, it is possible to optimize different web pages for different search queries.
  3. Backlinks vs App Downloads: Search engines rely on the amount and quality of backlinks to determine the authority of a website. App stores rely on app download velocity to assess authority. The more downloads an app receives over an amount of time, the higher the ranking chances of the app.
  4. Page Speed vs Uninstall Rate or Retention Rate: Both search engines and app stores want to provide users with the best user experience. Search engines, therefore, prioritize websites with fast page speeds in the search results. On the other hand, app stores rely on user metrics such as Uninstall Rate or Retention Rate to feed their algorithm.

Why Is ASO Important?

There is no question that App Store Optimization should be part of every mobile marketer’s marketing stack, especially for the following reasons:

  1. Over 65% of app downloads come from app store searches. This means that if you’re not investing in ASO, you’re missing out on the largest discovery channel available to your app.
  2. Every single user eventually comes through the app store to download your app. Whether users land on your app page via search ads, social media ads, or native ads, your app page plays a major role in convincing these users to download your app. A well-optimized app page will lead to a higher conversion rate and lower CPIs for your advertising campaigns.
  3. Overall, app retention rates are low and dropping year over year. But the 30-day retention rate for organic installs is, on average, 25% higher than non-organic installs and dropping at a much slower pace. Instead of wasting dollars on user acquisition, more and more mobile marketers are turning to ASO and spending their advertising dollars to re-target and engage higher quality users.
  4. There are more than 2 million apps in the app stores, so getting featured on the stores is an opportunity that comes to very few. The more you follow the store’s best practices (strong creatives, a video, localized listings in each country, and strong reviews), the higher your chances are of getting featured.
  5. Your competitors are doing it! AppTweak data shows that over the last year in the US App Store, the top 30 apps in the Shopping Category updated their icon almost 4 times. Apps in the Games Casual Category updated their title at least once and their description twice.

    Average metadata updates of the top 30 apps in the Shopping Category and Games Casual Category in the App Store in the US. Source:

  6. ASO works! There is no question that when executed carefully, ASO can generate excellent results. Have a look at a recent case study on how Ninja Number used ASO to grow downloads for their Android app by 300%.

Learn more about the impact of ASO

App Store Search Behavior

According to Apple, most apps are discovered through app store searches. More specifically, up to 65% of all downloads are generated by users who search for a specific keyword in the app store.

AppTweak dug deeper into these numbers and found that more than one-third of these searches (38%) were generic, non-branded searches.

 65% of all app downloads come from a search

65% of app downloads come from a search; almost one-third of these searches were generic, non-branded searches. Source:

However, the division between downloads from branded vs generic keywords varies strongly from app to app. Famous brands like Uber receive almost 80% of downloads from branded keywords or misspellings. But other apps, such as scanner apps or certain games that usually don’t have as strong a brand name, might receive more downloads from generic keywords than branded keywords. For example, AppTweak data shows that both Adobe Scan and Elevate Brain Training receive almost 75% of downloads from generic keywords.

division between downloads from branded vs generic keywords varies strongly from app to app

Famous brands like “Uber” receive almost 80% of downloads from branded keywords or misspellings. But “Adobe Scan” and “Elevate Brain Training” receive almost 75% of downloads from generic keywords. Source:

What Are the ASO Ranking Factors?

To get started with App Store Optimization, you need to understand the app store algorithms. The App Store and Google Play have their own unique algorithm, but the main ranking signals are similar:

1. Keywords in Metadata

For app stores to decide whether to rank your app on a certain keyword, the algorithms look at the keywords provided in the metadata (title, subtitle, and keyword field for iOS apps; title, short description, and long description for Android apps). If the keyword that users searched for has been added to your app’s metadata, your app has a chance to rank for that search term. The app store algorithm will further assign your app a higher rank if the keyword is contained in your app title, over the keyword field, or in the long description. As a general rule of thumb, keywords in the app title carry more weight than keywords in the subtitle, which, in turn, carry more weight than the iOS keyword field or long description.

Expert Tip

When looking at the live search results for the keyword “jigsaw puzzle” or “yoga” in the Google Play, you can see that all the apps that rank have this keyword in their title. This suggests that apps that don’t have this keyword in their title have a lower chance to rank.

Live search results for the keyword “jigsaw puzzle” and “yoga” in the US Google Play.

2. App Download Volume and Velocity

The number of daily app downloads is one of the strongest ranking signals in both the App Store and Google Play. A high number of daily downloads will help increase your ranks on a wide variety of terms.

Expert Tip

In March 2020, downloads soared for “Words with Friends 2” on the App Store in the United States, likely due to an advertising boost. We see a very similar trend in AppTweak’s Visibility Score. If we dig deeper on a keyword-by-keyword level, we indeed see that for general keywords like “games” or “best games,” rankings soared as downloads increased. Rankings for general keywords like “crossword puzzle” or “word puzzle games” also grew, but at a slower rate.

Visibility Score and App Download Estimates for “Words with Friends 2” in the US App Store.

3. Conversion Rate

The algorithms also account for conversion rate (the share of people who download your app after seeing it in the search results). Both the App Store and the Google Play want to provide users with a great user experience by showing the best possible apps in search results. If your app has a stable conversion rate for a specific keyword, it signals to the store that users are satisfied with the apps the algorithm is showing.

4. Ratings and Reviews

The number of reviews and your star rating represent another major ranking factor. Having a lot of positive reviews signals to the algorithm that users tend to like your app. It is, therefore, important to encourage your users to leave reviews and ratings in order to increase your app’s weight on the algorithm.

Expert Tip

In 2019, Apple updated its algorithm to allocate more weight to the average rating. Based on data of the top 500 iOS apps, AppTweak found that apps with a high rating, on average, rank 25 positions higher than apps with a medium rating and 60 positions higher than apps with a low rating

Apps with a high rating rank higher than apps with a medium or low rating.

Apps with a high rating rank greater than apps with a medium or low rating. Source:

5. Retention Rate

The stores do not solely rely on app downloads but also consider an app’s retention rate. If a lot of users uninstall your app shortly after it was downloaded, it signals to the algorithm that users were not happy with the app. Many argue that metrics such as session duration or the number of launches are also ranking signals.

6. App Performance

If your app is not well built and crashes often, or consumes a lot of battery on users’ phones, the algorithms (especially for the Google Play) will rank your app below others.

The Google Play algorithm also looks at the number of backlinks your app’s webpage has received. Similar to SEO, the more backlinks, the higher your app’s authority. A high authority signals that your app is widely known and will result in a higher rank.

How is ASO Different for the App Store and the Google Play?

The App Store and Google Play have the same objective – to help users discover and download new apps. But both stores have a very different look and feel when it comes to app page and search results. Some of these differences have a major impact on how you should optimize your app.

The search results and app page in the App Store vs Google Play. The Google Play images are shown in Dark Mode.

Main Differences in Search Results Between App Store and Google Play

In the App Store search results, apps appear alongside an app icon, title, subtitle, ratings, and screenshots. When the developer opts for portrait screenshots, 3 are shown in the search results. If landscape screenshots have been used, only 1 is shown. If the developer adds a portrait app preview video, the video will be placed before the first portrait screenshot and autoplay as users scroll down the search results page. Apple allows titles of up to 30 characters, but in the search results, the title is usually cut off at 18 characters.

Since the creative elements take up so much space, a maximum of two apps are shown on a phone screen. To see more, users have to scroll down. As a result, apps that are listed below the 10th position receive very little views.

The search results in the Google Play look very different for branded or general searches.

Search Results for the general term “rpg game” vs branded term “YouTube music” in the Google Play.

Depending on the device, up to 8 apps can be shown in the search results for a generic keyword. Apps appear with the app icon, title, developer name, ratings, and the average number of daily downloads. In contrast to the App Store, screenshots, videos, and the short description do not show in Google Play search results for generic keywords. Previously, Android titles were allowed to be up to 50 characters, but with the recent Google policy update in April 2021, app names are required to be only 30 characters, similar to the app title requirement in the App Store. Again, depending on the device, the title may be cut off in the search results .

When searching for a branded keyword, the corresponding app occupies most of the screen and appears with the app icon, title, developer name, ratings, downloads, screenshots, and short description. Underneath the app card, Google shows a carousel with “You might also like” and “Similar Apps”. Only below that (underneath the fold), you will find a list with apps that rank organically on this branded keyword.

Recently, Google has also begun to add tags to certain games. The first tag is usually the same as the game’s category; the second and third tags reflect game features such as “offline” or “multiplayer.”

To help users discover more apps, both stores include additional elements in the search results. On the App Store, you can find Editorial Collections, Stories, and in-app subscriptions. On Google Play, Google displays suggestion cards such as “You Might Also Like” or “Similar Apps.”

Main Differences in the App Page Between App Store and Google Play

Banner or Featured ImageOnly shows for certain apps at the top of the page.There is no option to add a banner.
App IconVery visible at the top of the app page and in the search results.Very visible at the top of the app page and in the search results.
App Title30 Characters – Shows next to the icon at the top of the app page and search results.30 Characters – Also shows next to the icon at the top of the app page and search results.
Developer NameShows underneath the app title on the app page, but automatically changes to display the subtitle after a few seconds. Also shows in the information panel on the app page.Is clearly visible and shows underneath the app title in the search results and on the app page.
Subtitle or Short Description30 Characters – Shows underneath the app title in both the search results and app page and is usually cut off at 26 characters.80 Characters – Shows underneath the screenshots on the app page. When using portrait screenshots, the short description will usually be shown below the fold.
Information PanelDisplays total number of ratings and average star rating, age, place in the category, top charts, developer name, languages in which the app is available, and size. The information panel is displayed above the screenshots and users need to scroll through it horizontally to see all the info.Displays total number of ratings and average star rating, total downloads, and age. The information panel appears above the install button and screenshots.
ScreenshotsEither portrait or landscape screenshots can be added. Portrait screenshots take up most of the space and push down the first few lines of the long description below the fold. Up to 10 screenshots can be added in total.Portrait screenshots display smaller and narrower in Google Play. Google does not have specific size requirements, but does recommend always adding at least 3 landscape screenshots so that the app is eligible to show in other places across the Play Store. Up to 8 screenshots can be added.
VideoUp to 3 preview videos can be added. Videos can be either in portrait or landscape mode and will be shown in the carousel before the screenshots on the app page and in the search results.Only one promo video can be added to the store listing. The video will appear in the carousel before the screenshots on the app page. It is recommended to add a featured image, which will serve as overlay for the promo video.
Keyword Field100 Characters – The keyword field is not visible on the app page, but Apple does index the keywords added to the keyword field.There is no option to add keywords in a keyword field for Android apps.
Long Description4,000 Characters – The first three lines are shown underneath the screenshots. To read the full descriptions, users have to click the "learn more" button. The keywords in the long description are not indexed in the App Store.4,000 Characters – No longer visible on the app page. Users need to click on the "arrow icon" next to the short description underneath "about this app" to read the long description.

How Differences Between App Store and Google Play Impact ASO

Search results, app pages, and the algorithms of the App Store and Google Play clearly look very different. These distinctions definitely impact how developers and mobile marketers should optimize their app store listings:

  1. The app name is a strong ranking signal in both the App Store and Google Play. But since the short description and screenshots do not show for general keywords in the Google Play search results, the title plays a major role in expressing what your app is about and convince users to download your app over competitors’.
  2. The subtitles vary widely in length for the App Store vs Google Play (30 characters vs 80 characters, respectively), and they also serve different purposes. In the App Store, the subtitle appears underneath the title in the search results; hence, it should explain to users what your app is about. For Android apps, the short description appears only on the app listing below the screenshots, and should focus on grabbing the user’s attention while convincing them to download your app.
  3. Apple still relies on a 100-character keyword field to decide which keywords to rank your app for. Google does not have such a keyword field and looks at long-tail keywords added in the title, short description, and long description.
  4. The long description is an important ranking factor in Google Play, but keywords used in the long description don’t rank in the App Store. Therefore, mobile marketers should optimize their Google Play long description following SEO principles and increase the density of top-priority keywords. The long description in the App Store does not need to be written with keyword optimization in mind.
  5. Apple recommends not repeating keywords in the title, subtitle, and keyword field. Furthermore, it is advised to add single keywords to the keyword field (no long-tail keywords) because Apple will automatically make combinations between all the keywords used in the title, subtitle, and keyword field. Google’s algorithm is more advanced and applies standard SEO best practices in their algorithm. Therefore, mobile marketers should define their top single and long-tail keywords, and increase the density of these keywords in their app page without running into the practice of keyword stuffing.
  6. Screenshots show up in App Store search results; but since iOS 15, screenshots don’t show anymore in the App Store if you have downloaded the app. In the Google Play results, screenshots show up for branded searches. It is recommended to add captions to your iOS screenshots that highlight your app’s main features or value proposition to make your app stand out in the search results. Furthermore, screenshots on the Android app page are smaller than screenshots on the iOS app page, hence it is advised to be very careful when adding captions on Google Play as they are harder to read.
  7. Google Play accounts for backlinks in their algorithm. Apple does not.

Learn more about the differences between ASO in the Apple App Store & Google Play Store

How to Get Started with ASO

Now that you know all about App Store Optimization ranking signals, the app store algorithms, and user search behavior, it’s time to get started and increase your organic downloads! Have a look at the tips below to discover what to focus on first. Need some help crafting an ASO strategy? Check this article out.

1. Identify Your Competitors

As a first step in your ASO strategy, you have to identify which apps you are competing with and what their strategy is. When identifying your competition, you should not only consider direct competitors, but also apps or games competing for the same keywords in the app stores.

2. Analyze Your Competitors’ ASO Strategies

Before you start digging into keyword research, take a step back and have a look at what your competitors are doing in terms of ASO. Not only can you learn a lot from this exercise, it will also help you define realistic benchmarks or KPIs for your own strategy. An ASO tool like AppTweak can make this research a lot easier!

With AppTweak’s ASO Timeline feature, you can find out exactly when a competitor implemented a metadata update and see a Before/After view of the update to see what has changed.

AppTweak's aso timeline feature

Screenshot of AppTweak’s ASO Timeline feature showing the before and after screenhots of Headspace in the US App Store.

3. Audit Your Current Performance

Before you start optimizing different elements of your app page, you have to carefully audit your current performance. How is your current metadata performing? Is your app ranking on the keywords targeted in the app title or subtitle? Do these keywords drive volume and downloads to your app? This part of your research will make sure you don’t remove any keywords that are driving downloads to your app, while replacing those keywords for which you lack visibility.

With AppTweak’s Ranked Keywords feature, you can see all the keywords for which your app ranks. Powerful metrics such as “Volume” help you understand how often this keyword is searched for. The “Installs” metric shows an estimation of how many downloads each of these keywords brings to your app.

apptweak's keyword analysis feature

Screenshot of AppTweak’s Keyword Analysis feature showing valuable metrics such as “volume,” “rank,” and “installs” to help assess the performance of each keyword.

4. Find Relevant Keywords

Now, let’s start with keyword research. To maximize your app’s visibility in the app stores, it is important you understand which keywords are used when your product/service is searched for in the app stores. A good place to start is by listing all the main features or benefits of your app. You can also scan the pages of competitor apps to find out which keywords they are targeting in their title or subtitle. But, to truly find unique keyword opportunities (high volume keywords for which your competitors lack visibility), it is best to invest in an ASO tool. AppTweak has more than 11 keyword research features to help you find the most relevant keywords for your app.

Advanced ASO Keyword Research Guide

A deep-dive into ASO keyword research. Learn how to find and prioritize your target keywords, localization, and ASO best practices.

Download this guide

5. Update Your Metadata

Once you have built a list with keywords that are relevant to your app and that describe your product or service, you need to decide which keywords you should add to your metadata.

Keep the following tips in mind when selecting keywords:

  • Choose keywords that are most relevant to your app and provide an answer to a user query.
  • Choose keywords with a medium or high volume.
  • Make sure to add the most important keywords to your app title as it contains the most weight in both the App Store and Google Play.

6. Optimize Your Visual Elements

Throughout this article, we have explained how important your visual elements are when it comes to conversion rate optimization. Take the time to design well-thought screenshots and videos. Google Play has a very useful A/B testing feature that allows you to test different versions of your creative, so that you can find out which one resonates best with your audience (and will therefore drive up your app’s conversion rate).

To measure the impact of both your keyword updates and creative updates, we recommend establishing a timeline so you can plan your updates at different times.

7. Localize Your App

App stores reach global audiences, so, to really increase your app’s visibility around the world, it is very important to localize your app. App localization is the process of adapting your app (including the metadata, keyword field, and screenshots) to all the different languages and cultures you want to target. Localization goes beyond just translating your app’s metadata and graphic assets. People in other countries might search differently, which means that to be effective, you need to properly research which keywords people are using in your target country and optimize your metadata accordingly. Keep in mind that there might also be local competitors you need to monitor to spot additional opportunities.

8. Get More User Reviews

Ratings and reviews are a major ASO ranking signal and should be a key part of your ASO strategy. Start by asking friends and family to review your apps. Then consider adding a pop-up, asking people to review your app. However, keep in mind that when asking for a review, timing is really important. Only ask people to review your app after they have used it a few times or when they have completed an action or event on your app.

9. Monitor Rankings and Visibility

It is vital to monitor your app rankings and visibility on a regular basis. Not only do the app stores update their algorithm regularly, new competition is constantly launched on the app stores and user search behavior changes over time. Make sure to spot trends early and adjust your keyword strategy when necessary.

Expert Tip

Regularly updating your app’s metadata in the App Store and Google Play is one of the most efficient ways to ensure your app’s visibility. In general, we recommend to review and update iOS metadata every 4 weeks and Google Play metadata every 4–6 weeks.

Find out how often top apps or competitors update their metadata with AppTweak’s Update Frequency & Benchmark feature

Pre-Launch ASO: Optimizing Your App for a Successful App Launch

Even when your app is not in the app stores yet, it is important to carefully prepare your ASO strategy to maximize visibility. Both Apple and Google give a small boost to new apps. If done right, this small boost could result in long-term visibility on your main keywords.

The steps to take to optimize your ASO before your app launches do not differ much from the steps explained earlier:

  • Identify and audit competitor’s metadata and ASO strategy. Try to dig into past updates to understand what worked for them and what did not.
  • Start with keyword research and identify high-volume and relevant keywords. Have a look at competitors and find out which keywords they rank for and find the hidden gems for which they lack visibility.
  • Craft an app title, subtitle, and long description that carefully explains what your app is about, taking into account the target keywords identified in the keyword research process.
  • Design engaging creatives that make your app stand out from the competitors in the search results.
  • Once your app is live, you need to give both algorithms some time to correctly rank your app on your target keywords. Make sure to keep a close eye on the progress and adjust keywords if needed.

Test Your ASO with a Soft Launch

Soft launching implies releasing an app or game in a secondary market. For example, many game developers launch their app in markets like New Zealand or Norway to gather user feedback and unveil some bugs before the worldwide app launch. A soft launch can also be used to test your ASO strategy. It allows you to understand keyword performance and test which creative generates the highest conversion rate.

Generate Buzz through Pre-Order (iOS) or Pre-Register (Android)

You can build excitement and an audience for your app by making it available for pre-order (App Store) or pre-register (Google Play). Your app will appear in the store, but instead of downloading the app, users can pre-register for it. Then, once the app is released, users will receive a notification and the app will automatically be downloaded on the device (for Google Play, users have to opt in for the app to be automatically downloaded).

Pre-order apps have their own (simplified) app page and can appear anywhere in the App Store (search results and even the “Today” tab and “Apps” or “Games” tab if it’s featured). Pre-order apps are indexed in the store and can rank on the keywords targeted in the metadata. This allows you to test keyword and creative performance early on.

Also, apps available for pre-registration on the Google Play are searchable in the store. To encourage users to pre-register for your app, Google provides the option to offer “pre-registration rewards” – an in-app product such as a special character or extra lives that users will receive after the app is released. Developers can also provide a Google Play Instant experience, which allows users to engage with the app or game before the official launch. This can help to drive pre-launch buzz and engagement.

ASO in 2022

At the annual World Wide Developer Conference hosted in June 2021, Apple unveiled the most important release of this year – iOS 15 and some of its important features that will impact ASO in 2022. These include A/B testing for creatives in the App Store, custom product pages, and in-app events.

AppTweak regularly writes about the latest updates in the app stores. Here are some quick links to the trending topics related to the latest release of iOS 15:

New Policy Guidelines on Google Play

Google announced important policy changes for app metadata, effective from 29 September 2021, with the purpose to improve app quality and discoverability for Android developers on Google Play. To uncover more on what, why, and how these changes were introduced, check out this blog on Google Play’s metadata policy changes.

Are you ready to start optimizing your ASO? AppTweak is the #1 ASO tool for apps and games driven by data science! Sign up today for a 7-day free trial!

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Alexandra De Clerck

by ,  Head of Marketing at AppTweak

Alexandra De Clerck is Head of Marketing at AppTweak. She has helped many companies increase their online web presence and is now here to help you boost your app downloads.