The complete ASO guide.

What ASO actually is

App Store Optimization (ASO) is the practice of improving two distinct numbers: how often your app appears in App Store and Google Play search results (visibility) and how often a listing view turns into an install (conversion rate, or CVR).

These two levers are multiplicative. Doubling visibility while keeping CVR flat doubles installs. Doubling CVR while keeping visibility flat also doubles installs. Doubling both gives 4×. Serious ASO work optimizes both in parallel.

The ranking factors (in order of impact)

App Store and Google Play do not publish their ranking algorithms. What follows is the consensus from a decade of ASO research, public patents, and empirical A/B testing.

iOS (App Store)

1. App name / title — up to 30 chars. Highest-weighted keyword signal.
2. Subtitle — up to 30 chars. Second-highest keyword signal.
3. Keyword field — up to 100 chars, comma-separated, not user-visible. Pure keyword signal.
4. Bundle ID / URL — minor signal, largely locked after launch.
5. In-app purchase names — indexed, minor signal.
6. Ratings and reviews — quality and velocity both matter.
7. Install velocity and retention — strong behavioral signal.
8. Description — low direct ranking signal, but affects conversion.

Android (Google Play)

1. App name / title — up to 30 chars.
2. Short description — up to 80 chars. Higher weight than iOS subtitle.
3. Long description — up to 4000 chars. Meaningfully indexed, unlike iOS.
4. Ratings and reviews.
5. Install and engagement metrics.
6. App category.

Keyword strategy

Keyword research for apps is similar to SEO keyword research with two critical differences: mobile search queries are shorter (most are 1-2 words), and there's no long-tail traffic to speak of (if a keyword gets <100 searches/day, it's not worth optimizing for).

The 3-tier keyword model

1. Head term — 1-2 words, high search volume, high competition. Example: "budget app," "workout tracker." Go after these only if you have the metric chops (lots of reviews, high CVR).
2. Mid-tail — 2-3 words, medium volume, medium competition. Example: "budget app for couples," "bodyweight workout tracker." The sweet spot for most apps.
3. Long-tail / branded — 3+ words or misspellings of competitors. Low volume but almost free to rank for.

Research tools

• App Store autocomplete — type the start of your category term; Apple's autocomplete shows you what's actually searched.
• Google Play autocomplete — same approach.
• Competitor metadata — read your top 5 competitors' app names, subtitles, and descriptions. Reverse-engineer their keyword set.
• Paid tools — AppTweak, AppFollow, Sensor Tower, data.ai. Useful but not required for a startup.

Metadata — titles, subtitles, descriptions

App name / title (30 chars, both stores)

This is the single most important metadata field. Two patterns that work:

• Brand + keyword — "Nuvex: AI Screenshot Maker," "Lumi: Sleep Tracker." Gets you both branded and generic search traffic.
• Keyword + differentiator — "Budget App for Couples," "Chess with AI Coach." Leans into generic search, works for new brands with no recognition.

Subtitle (iOS, 30 chars) / Short description (Android, 80 chars)

The second-most important field. Pack it with different keywords than the title. Do not repeat title words — it wastes the budget.

• iOS subtitle example: "Track runs, swims & HIIT workouts" (30 chars)
• Android short desc example: "Track runs, swims, HIIT, cycling & strength. No subscription required. Offline." (80 chars)

Keyword field (iOS only, 100 chars)

Comma-separated. No spaces after commas (wastes chars). Never repeat words already in title or subtitle (redundant). Focus on mid-tail and long-tail here — head terms won't rank without title placement.

Example for a workout app: weightlifting,dumbbell,home,bodyweight,push,pull,legs,gym,HIIT,cardio,stretch,yoga,abs

Long description

iOS: 4000 chars. Android: 4000 chars. On iOS this is primarily a conversion tool (users read the first 2 lines above "more"). On Android, it is indexed — so write it dense with keywords in natural prose.

Visual assets — icon and screenshots

Visual assets are where conversion rate lives. You can rank #1 and still lose to a competitor with better screenshots.

App icon

• Instantly recognizable at thumbnail size (60px)
• High contrast against both light and dark App Store backgrounds
• No text (text is illegible at thumbnail size and violates Apple guidelines)
• Distinctive shape — look at the row of 10 competing icons in search; yours should stand out visually

Screenshots

See our dedicated screenshot guide and sizes reference. Key points for ASO:

• First 2-3 screenshots appear in search results without opening the listing
• Headline must be readable at thumbnail size
• Match the first screenshot's promise to the keyword the user searched
• Localize screenshots per market — not just translate metadata

Conversion rate (CVR) optimization

CVR in the App Store is typically 2-5% for mid-quality listings and 10-20% for top-tier optimized listings. There's massive upside.

The CVR formula

CVR = f(icon, screenshots, rating, reviews, subtitle, category)

In practice, screenshots move CVR more than anything else once your icon and rating are adequate. Investing design budget in screenshots almost always pays back faster than anywhere else.

Quick CVR wins

• Replace generic "app preview" screenshots with headline-driven, benefit-focused frames
• Get your rating above 4.5 stars (prompt for review at positive moments inside the app)
• Add or fix your subtitle — a compelling 30-char subtitle can add 10-15% CVR
• Re-shoot the first screenshot to be benefit-focused, not feature-focused
• Lead with your strongest review quote in the description's first 2 lines

A/B testing — Product Page Optimization & Experiments

Apple: Product Page Optimization (PPO)

Free, built into App Store Connect. Lets you test up to 3 variants against your current "treatment" (original). You can test:

• Icon
• Screenshots (per device class)
• App Preview video

Apple splits traffic evenly across variants and shows you install rate per variant. Typical test needs 2-4 weeks to reach 95% confidence at 1000-5000 daily installs.

Google: Store Listing Experiments

Free, built into Google Play Console. Lets you test:

• Icon
• Feature graphic
• Screenshots
• Short description
• Full description
• Promo video

Google shows statistical significance automatically and can target experiments to specific countries.

Localization strategy

Localization is the single most-overlooked ASO lever. Most indie apps ship with English metadata only and lose 30-50% of potential installs to localized competitors.

The minimum viable localization

• Translate app name (if culturally appropriate — keep brand names), subtitle, and keyword field into your top 5 markets
• Translate the first 2 lines of the description (the only ones most users see)
• Generate locale-specific screenshots — copy translated, composition adapted to cultural expectations

Top markets to localize to (by volume)

1. United States — English
2. China — Chinese (Simplified) [iOS only; Google Play not available]
3. Japan — Japanese
4. Germany — German
5. Brazil — Portuguese (Brazilian)
6. France — French
7. South Korea — Korean
8. United Kingdom — English (UK)
9. India — Hindi, then English
10. Spain / LATAM — Spanish

Ratings and reviews

• Get above 4.5 stars. Below that, CVR falls off a cliff. Above 4.5, returns diminish.
• Prompt for reviews at positive moments. After a completed purchase, a 7-day streak, a successful workout, etc. Never on first launch.
• Respond to 1-star reviews publicly. A respectful response visible in your listing can undo the damage of a bad review.
• Fix the issue in 1-star reviews. Ship the fix, update the listing, and ask the user to update their review.
• Ignore Apple's review prompt limit as a designer, not a developer. You get 3 per year per user — make them count.

Paid acquisition and ASO

Paid installs boost organic ASO on both stores. The stores interpret "lots of installs" as "this is a popular app" and rank it higher organically.

• Apple Search Ads — bid on competitor brand keywords and generic category terms. Your paid installs boost organic rank.
• Google App Campaigns — universal campaign type across Google Search, YouTube, Play, and Display.
• Meta & TikTok — creative-driven; don't directly boost organic ASO but drive install velocity.

How to measure ASO

• Impressions — how often you showed up in search
• Product page views — how often users tapped your listing
• Conversion rate (product page view → install) — your design's performance
• Install rate (impression → install) — a combined metric that blurs search vs conversion
• Keyword ranking — for your target keywords, tracked weekly
• Retention — Apple and Google both factor it into rankings

90-day ASO checklist

Week 1-2: Foundation

• Audit current metadata (title, subtitle, keywords, description)
• Research 20-30 target keywords across 3 tiers
• Rewrite title and subtitle for keyword + value prop
• Fill keyword field (iOS) with high-intent non-title words

Week 3-4: Visual assets

• Generate new screenshots with headline-driven, benefit-focused frames (Nuvex or designer)
• Update app icon if it's not instantly distinctive at thumbnail size
• Upload all required sizes to both stores

Week 5-8: Testing

• Set up Apple PPO and Google Store Listing Experiment
• Test one variable at a time (icon OR screenshots, not both)
• Run each test 2-4 weeks

Week 9-12: Localize

• Localize metadata to top 5 markets
• Localize screenshots (not just translate) to top 3 markets
• Measure install lift per market

FAQ

How long does ASO take to work?

Metadata changes: 1-2 weeks for iOS to re-index, 3-5 days for Android. Visual changes affecting CVR: immediate (days). A/B tests to statistical significance: 2-4 weeks at moderate install volumes.

Can I change my app name without losing rankings?

Yes, but transition risk is real. If you have brand recognition, keep the brand word and add a keyword. If you don't, you can safely rename — just do it once, not monthly.

What are realistic install numbers from ASO alone?

For a well-optimized app in a moderately competitive category, 50-500 organic installs/day is realistic after 6 months of ASO work. Top-tier apps hit 5000+ organic/day.

Is ASO a one-time job?

No. Stores update ranking algorithms, competitors improve, and your own app evolves. Treat ASO as quarterly maintenance work plus an annual deep audit.

Does Nuvex help with ASO?

Nuvex handles the single highest-leverage visual asset — screenshots. We do not do keyword research or A/B test management (those are separate tools). Our view: better screenshots beat marginally better keywords most of the time.