ASO stands for App Store Optimization. It is the practice of improving how an app ranks in app store search and how many of the people who see your store listing actually install it. In marketing terms, it is the app store’s equivalent of SEO: the work that gets your app discovered and chosen without paying for every install.
If you are an indie iOS developer who just shipped an app and downloads are flat, ASO is the lever you are missing. Here is what it actually covers.
The Two Jobs of ASO
ASO does two things, and it helps to keep them separate in your head:
- Visibility — getting your app to show up when someone searches a relevant term, or browses a category, on the App Store. This is the ranking side.
- Conversion — turning the people who land on your product page into installs. This is the part that happens after you are visible.
You need both. Ranking number one for a keyword nobody converts on wastes your visibility. A beautiful product page that nobody ever sees wastes your conversion work. Good ASO balances the two.
The Parts That Make Up ASO
Keywords and metadata
The App Store reads your app title, subtitle, and the 100-character keyword field to decide which searches you rank for. These three fields are the core of search visibility. Choosing the right terms, placing the highest-value ones where they carry the most weight, and never wasting characters by repeating words is the foundation. Start with how to pick keywords that actually rank and the App Store keyword field.
Screenshots and preview video
Your screenshots and preview video are the biggest driver of conversion, and on iOS the text in your screenshots is also read by Apple’s OCR as a ranking signal. They are part of ASO, not just design. See why your screenshots are part of ASO.
Ratings and reviews
Ratings volume and average score influence both ranking and the decision to install. They are a core ASO input, not an afterthought. See app store ratings as ASO strategy.
Localization
Every language you add gives you another localized title, subtitle, and keyword field to rank in new markets. Localization is one of the highest-leverage ASO moves for an app that only ships in English. See app store localization.
Conversion signals
The App Store rewards apps that convert well. Your impression-to-install rate feeds back into your ranking, which is why visibility and conversion are not really separate systems. See impression to install rate.
How ASO Differs From SEO
If you know web SEO, the mental model transfers, but the mechanics differ:
- Less text to work with. A web page can rank on thousands of words. An App Store listing ranks mostly on a title, a subtitle, and 100 keyword characters. Every character matters more.
- No backlinks. App store ranking leans on download velocity, ratings, and metadata relevance rather than inbound links.
- Conversion is part of ranking. On the web, click-through and bounce influence rankings indirectly. On the App Store, your install conversion rate is a direct and powerful ranking signal.
- Slower feedback, with caution. Metadata changes can take days to settle, and changing too much at once can reset hard-won rankings. See the ASO timeline.
Why ASO Matters for Indie Developers
Most App Store installs still start with a search. If you are not paying for ads, that organic search traffic is the main way new users find you, and ASO is the only way to influence it. For an indie developer with no marketing budget, ASO is not a nice-to-have. It is the highest-return work you can do on an already-built app, because you are improving distribution without building anything new.
The good news: the apps you compete with are usually doing ASO badly or not at all. A developer who does the basics well, the right keywords in the right fields, screenshots that convert, a few localizations, can out-rank apps with far bigger budgets on the terms that matter.
Where to Start
If this is your first pass at ASO, start here:
- Read ASO for indie developers: the complete guide.
- Build a keyword list and learn to read keyword difficulty.
- Follow the 60-day ASO playbook to put it into a routine.
Try Marteso Free
Marteso gives indie iOS developers everything ASO touches in one place: keyword tracking, AI keyword discovery, metadata optimization pushed straight to App Store Connect, screenshot automation, and localization across 20+ locales.
The free tier gives you one app, 50 tracked keywords, and daily rank updates with no credit card required. Start at app.marteso.com.