Updated on 12 November 2026 by Nicolas Finet, CEO of Sortlist. We have rewritten this guide to be a practical ASO playbook: what app store optimisation is, how the Apple App Store and Google Play rank apps, the metadata and conversion elements you control, how to research keywords, how to test and measure, and common mistakes. The earlier version was very long and repeated points across sections; we reorganised it into a checklist you can apply, and flagged where the evidence is only industry estimates.
App store optimisation (ASO) is the process of improving your app's visibility in app store search and browse results, and increasing the share of people who view your listing and install the app. It is often compared with SEO, but it works inside Apple's App Store and Google Play, with different signals and a stronger link between listing conversion and ranking. Apple and Google do not publish full ranking weights, so most ASO guidance comes from vendors' tests and should be treated as industry estimates.
Key takeaways
- ASO has two jobs: discoverability (keywords and relevance) and conversion (icon, screenshots, rating, description turn views into installs).
- Title keywords carry the highest weight on both stores; each store indexes about 30 characters of the app name or title, according to ASO vendors.
- Apple has a 100-character hidden keyword field and does not index the long description for ranking; Google Play indexes the description and reads some web signals such as backlinks.
- Industry guides say both stores have shifted weight from pre-install signals (keywords, ratings, downloads) towards post-install signals such as retention and conversion.
- Optimise each store separately, test changes one at a time and measure impressions, conversion rate and installs.
ASO versus SEO
| ASO | Website SEO | |
|---|---|---|
| Where | Apple App Store and Google Play | Google, Bing and other search engines |
| Main goal | Installs | Visits and conversions |
| Key signals | Title and keywords, ratings, conversion rate, retention | Content, links, technical quality, authority |
| Metadata limits | Strict character limits | Flexible length |
| Testing | Store experiments and custom listings | A/B tests on your site |
Mobile SEO helps people find your website; ASO helps people find and install your app. Many apps need both. See our guide to mobile app design for the experience people reach after installing.
How the two stores differ
| Element | Apple App Store | Google Play |
|---|---|---|
| App name or title | About 30 characters; highest-weight keyword field | About 30 characters; highest-weight keyword field |
| Subtitle or short description | Subtitle (30 characters), indexed | Short description (80 characters), important for ranking |
| Keyword field | 100 hidden characters, comma-separated | No hidden field |
| Long description | Not indexed for ranking; important for conversion | Indexed; use keywords naturally |
| Screenshots | Up to 10 | Up to 8 (promo video optional) |
| Off-store signals | Not used in the same way; backlinks not a factor | Web signals such as links and mentions can influence ranking |
| Testing tools | Product page optimisation tests and custom product pages | Store listing experiments and custom listings |
Limits change, so check Apple's App Store Connect and Google Play Console documentation for the current specifications.
Ranking factors you control
Metadata (on-listing)
- Title. Combine your brand with the most important keyword, for example "Brand: Meal Planner". Keep it readable.
- Subtitle or short description. Add secondary keywords and a clear benefit.
- Keyword field (Apple). Use singular forms, avoid repeating words from the title and avoid spaces after commas.
- Long description (Google Play). Use primary and secondary keywords naturally; a 2% to 3% density is a rule of thumb, not a published rule.
- Category and localisation. Choose the best-fit category and localise metadata for each market, including UK English spellings.
Conversion elements
- Icon. Simple, distinctive and legible at small sizes.
- Screenshots and video. Show the value in the first two or three images, with short captions.
- Ratings and reviews. Volume, average and recency matter; ask for ratings at moments of success and respond to reviews.
- Description and social proof. Concise benefits, awards, press and features.
Behavioural signals (earned)
- Install volume and velocity from all sources.
- Retention and engagement. Apps people keep and use rank better over time.
- Uninstall and crash rates. Quality issues hurt visibility.
- Update frequency and technical quality. Stable, regularly maintained apps are favoured.
Sortlist editorial note: be sceptical of precise claims like "84% of improvements came from the short description". They usually come from a vendor's own dataset and cannot be verified. Run your own tests.
Sortlist editorial team
Keyword research and selection
- List candidate keywords. Features, problems solved, competitor terms, synonyms and autocomplete suggestions in each store.
- Check relevance. Only target terms that describe what the app really does.
- Estimate popularity and difficulty. Use ASO tools to compare search volume estimates and competition.
- Prioritise. Pick a mix: high-relevance mid-competition terms and long-tail phrases where you can rank.
- Place keywords by weight. Strongest in the title, then subtitle or short description, then keyword field or description.
- Track rankings. Monitor positions and impressions weekly and adjust.
Improving conversion: a testing plan
| Test | What to change | Metric |
|---|---|---|
| Icon | Colour, symbol, simplicity | Tap-through to listing and install rate |
| First screenshots | Order, headline, visual style | Conversion rate from view to install |
| Short description or subtitle | Benefit-led versus feature-led | Conversion and keyword rankings |
| Preview video | With or without video, first seconds | Install rate |
| Localised listings | Language and cultural fit | Installs by country |
Test one variable at a time and run tests long enough to gather meaningful data.
Measuring ASO
- Impressions and product page views (visibility).
- Conversion rate from page view to install.
- Installs by source: search, browse, referrals and paid.
- Keyword rankings for priority terms.
- Retention, rating and review sentiment.
- Revenue per install and cost per install if you run paid campaigns.
Worked example: a UK meal-planning app
A meal-planning app for UK families launches with the title "MealMate" and little else. It ranks for its brand name only. An ASO audit finds that none of its metadata contains the phrases people search for. The team researches terms in each store and finds that "meal planner", "weekly menu" and "family recipes" have healthy search interest and moderate competition. On Apple, the title becomes "MealMate: Meal Planner", the subtitle "Weekly menus and family recipes", and the 100-character keyword field is filled with related terms that are not already in the title or subtitle, such as "shopping list, budget, batch cooking, leftovers". On Google Play, the short description is rewritten to lead with the benefit ("Plan a week of family meals and build your shopping list in minutes") and the long description covers the same terms in natural sentences.
The team then tests two sets of first screenshots: one showing individual features, one showing the outcome (a full week planned in a minute). The outcome-led set lifts the view-to-install rate, so it becomes the default. Within two months the app ranks for several target phrases, and installs from search rise. The team keeps a log of every change and the date, so later movements can be tied to specific edits rather than guessed at.
Competitor analysis for ASO
- Identify the real competitors. They are the apps that appear for your target keywords, which may differ from business competitors.
- Review their metadata. Look at titles, subtitles and descriptions for repeated themes and keyword gaps.
- Study their visuals. Note how they lead with benefits, which screenshot styles dominate and where you can stand out.
- Read their reviews. Complaints reveal unmet needs you can address in your listing and product.
- Track changes over time. Competitors' updates can hint at what is working.
Managing ratings and reviews
- Prompt for a rating after a positive moment, such as completing a task, using the platform's native prompt, and do not ask too often.
- Reply to reviews, especially critical ones, with a helpful, polite message and a route to support. A thoughtful reply can change the reader's view, and some users update their rating after a fix.
- Use review themes to guide product improvements and update the listing when a major issue is fixed.
- Never buy, incentivise or fake reviews: they breach store rules and, in the UK, the Digital Markets, Competition and Consumers Act 2024.
Beyond the listing: supporting activities
- Website and landing pages. Link to your listing, explain the app clearly and use smart banners.
- Backlinks and PR (especially for Google Play). Mentions and links from relevant sites can help.
- Paid user acquisition. App store ads and social campaigns can add installs and improve visibility if users stay.
- Ratings prompts. Ask at a positive moment, using the platform's native prompts.
- Update cadence. Release notes can highlight new features and show the app is maintained.
UK considerations
- Localisation. Use UK English and local terms, and pricing in pounds including VAT.
- Privacy. Provide accurate privacy information and data-safety labels in line with UK GDPR and store requirements.
- Advertising claims. Listings and ads must not mislead; the CAP Code applies to claims in marketing, and ratings or reviews must be genuine (fake reviews are banned under the Digital Markets, Competition and Consumers Act 2024).
- Children. Apps likely to be accessed by children should consider the ICO's Age Appropriate Design Code.
Seasonality and updates
Search demand for many apps varies through the year: fitness apps peak in January, travel apps before holidays, tax and budgeting apps around deadlines. Refresh screenshots, descriptions and promotional text before peak periods, and use update notes to highlight relevant features. Keep a calendar of seasonal moments for your category and plan listing changes a few weeks ahead so they are indexed and tested in time.
Common ASO mistakes
- Stuffing keywords into the title so it reads poorly.
- Targeting irrelevant keywords that attract the wrong users and hurt retention.
- Copying the same metadata across both stores.
- Ignoring ratings and reviews.
- Changing several elements at once and not knowing what worked.
- Neglecting localisation and updates.
- Focusing on installs without checking retention and revenue.
A 30-day ASO plan
| Week | Actions |
|---|---|
| 1 | Audit the current listing, rankings, competitors and conversion; set targets |
| 2 | Research keywords; rewrite title, subtitle or short description and keyword field |
| 3 | Redesign icon and screenshots; prepare experiments; localise key markets |
| 4 | Launch tests, set up rating prompts and review responses; start tracking in a dashboard |
Frequently asked questions
What is ASO?
Improving an app's visibility and install rate in the App Store and Google Play.
How is ASO different from SEO?
ASO optimises listings inside app stores using limited metadata and in-store signals; SEO optimises web pages for search engines.
How long does ASO take to work?
Metadata changes can affect rankings within days to weeks; conversion and behavioural improvements take longer to show.
Do ratings affect ranking?
Ratings are a ranking input and strongly influence conversion.
Should I optimise differently for iOS and Android?
Yes. The two stores index different fields and use different signals, so treat each separately.
Want help launching or growing an app? Post your project on Sortlist and compare UK mobile marketing agencies for free.
Sources: AppRadar, ASO ranking factors in 2026, AppFollow, ASO ranking factors, AppTweak, what is app store optimisation, The App Launchpad, app store ranking factors. Ranking weights are vendor estimates; Apple and Google do not publish full details, and character limits should be checked in App Store Connect and Google Play Console.
