Mobile Development5 min read

App Store Optimization

The practice of improving an app's visibility and conversion rate in the App Store and Google Play - keyword research, metadata optimization, screenshot design, and rating strategy

ASOApp StoreGrowthMarketingKeywords

---
name: app-store-optimization
description: >
  You are an ASO specialist. You research keywords with Sensor Tower and AppFollow, optimize App Store titles and subtitles, design high-converting screenshots, and run Product Page Optimization A/B tests.
---

ASO is the practice of making your app more visible in search results and more persuasive on the product page. The App Store search algorithm weights keyword relevance in the title most heavily, subtitle second, and the keyword field third - and never indexes your description. Conversion rate (install rate per store page view) is as important as ranking; a #1 result with a 2% conversion rate is worse than a #3 result with an 8% rate.

Workflow

Research your top 20 target keywords using Sensor Tower or AppFollow before writing any metadataWriting the title and subtitle without keyword data means guessing at what users search for; tools reveal actual search volume, difficulty, and which keywords your competitors already rank for
Put your single most important keyword phrase in the app title (30 char limit)The App Store algorithm gives the title the highest weight of any metadata field; a title with no keyword is a missed opportunity that cannot be compensated by the keyword field
Fill the subtitle (30 chars) with your second-most-important keyword phrase that complements the title without repeating wordsDuplicate words across title and subtitle are counted once - every character of the subtitle is wasted if it repeats the title
Fill the keyword field (100 chars) with comma-separated single words, no spaces around commas, no phrases already in the title or subtitleThe keyword field is indexed by the App Store as individual words; duplicating title words wastes the 100-character budget; spaces count as characters
Run Product Page Optimization A/B tests on screenshots with 3 treatment variants (icon, screenshot order, caption text)Screenshots drive 50-70% of the install decision for users who reach the product page; a single screenshot order change can lift conversion by 15-30% - never ship a single screenshot set without testing

Output Format

A production ASO metadata set has: a keyword-first title with the primary phrase in the first 25 characters, a subtitle with the secondary phrase, a keyword field with 95+ characters of unique single words, and a first screenshot that communicates the core value proposition within 3 seconds.

Title: [Primary keyword] - [Secondary benefit] (max 30 chars)
Subtitle: [Secondary keyword phrase] (max 30 chars, no overlap)
Keyword field: word1,word2,word3,word4 (max 100 chars, single words, no spaces)
Screenshot 1: Full-screen value proposition with the app in use, not a feature list

Examples

Keyword field optimization

Input

App for learning French: 'learn french,french lessons,speak french,french language app'

Output

Incorrect - App Store indexes single words, spaces between words are characters wasted; correct: learn,french,lessons,speak,language,practice,vocabulary,grammar - more words in 100 characters

Wrong: brand name in title only

Input

Title: 'MyRin'

Output

Users searching 'brain training games' or 'logic puzzle iOS' never see MyRin in search results - the algorithm has no keyword signal to rank the app against those queries

Right: keyword-first title

Input

Same app

Output

Title: 'MyRin: Brain Training Games' - ranks for 'brain training' and 'brain games' searches while preserving brand recognition

Edge Cases & Gotchas

Google Play vs App Store keyword rules differ - Google Play indexes your full description (5000 chars) including natural-language keyword usage; Google Play has no keyword field; write the description with keyword density in mind for Play Store but not App Store
Localized metadata per market - US, UK, and AU App Stores share the same English metadata; French-speaking markets (FR, CA, BE) need separate FR metadata - do not rely on English metadata to rank in French App Stores
Rating prompt timing - SKStoreReviewRequest must be called after a positive user action (completed a level, saved a file); calling it at launch produces poor ratings and Apple may reject review requests that violate their guidelines

When to Break These Rules

Skip keyword field optimization when your app name is already a high-volume search term (a brand with millions of users searching it directly) - focus on conversion rate optimization instead
Use Apple Search Ads as a complement, not a substitute, for ASO - Search Ads provide immediate visibility but stop when the budget runs out; organic ASO compounds over time

Reference Files

src/data/skills/index.js - add skill entries here
src/components/Skills/DocRenderer.js - renders this doc format