Asc aso

App Store Optimization (ASO)

Maximize organic discoverability and conversion on the App Store. Submission mechanics live in asc-submission; pricing lives in app-store-pricing. This skill is about being found and chosen.

ASO has two halves:

1. Discoverability — ranking for the searches your users actually type (driven by the indexed text fields).
2. Conversion — turning a product-page visit into an install (driven by the visual/first-impression assets).

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The Indexed Fields (what Apple searches)

Apple builds its keyword index from the union of these fields. Order and weighting matter.

Field	Limit	Indexed?	Weight	Notes
App name / title	30 chars	✅	Highest	Brand + 1–2 strongest keywords
Subtitle	30 chars	✅	High	Second-strongest keywords; visible under the name
Keyword field	100 chars	✅	Medium	Comma-separated, no spaces, hidden from users
In-app purchase name/desc	30/45 chars	✅ (light)	Low	IAP display names are lightly indexed
Developer name	—	✅	Low	—
Description	4000 chars	❌	None (iOS)	Not indexed on Apple — write for humans/conversion
Promotional text	170 chars	❌	None	Editable without review; not indexed

Apple ≠ Google Play. On the App Store the long description is not indexed. Don't keyword-stuff it. (Google Play does index the description — keep that distinction if you ship both.)

The golden rules of the keyword field

• Never repeat a word across title, subtitle, and keyword field — Apple indexes the union, so repetition wastes characters. Each keyword appears once, in exactly one field.
• No spaces after commas: focus,timer,pomodoro not focus, timer, pomodoro (spaces burn characters).
• No plurals if you have the singular — Apple matches stems reasonably; spend characters on distinct terms.
• Don't include your app name or category name — those are already indexed.
• Don't use competitor trademarks — rejection / legal risk.
• Singular words combine — time,management lets you rank for "time management" without spending on the phrase. Apple auto-combines indexed words into phrases.

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Keyword Research Workflow

1. Seed list — brainstorm what a non-user would type to find the app's job-to-be-done (not your feature names). Think intents: "track water", "split bills", "white noise".
2. Expand — for each seed, gather synonyms, related jobs, and long-tail variants.
3. Score each candidate on three axes:
   • Relevance — does the app genuinely satisfy this search? (Irrelevant keywords tank conversion and ranking.)
   • Volume — how many people search it? (High volume = more traffic if you rank.)
   • Difficulty — how entrenched are the top results? (New apps win on low-difficulty, high-relevance long-tail first.)
4. Allocate — strongest term → title, next → subtitle, the rest → keyword field by descending value until 100 chars are full.
5. Localize — repeat per locale (see below). This is where most apps leave the most traffic on the table.

New apps: win the long tail first. Don't fight "fitness" on day one. Rank #1 for "interval timer for boxing", accrue ratings + conversion velocity, then climb to broader terms.

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Localization = free traffic

Each localization is a separate keyword index. You can add keywords in other locales' fields even when the app UI is English, and you inherit traffic from locales that share a base.

• English has two storefront locales — en-US and en-GB (English UK). en-GB is indexed for many non-US English-speaking storefronts. Filling en-GB keywords doubles your English keyword budget for free.
• Localize at least: en-US, en-GB, and your top revenue locales' languages.
• Localize screenshots and subtitle, not just keywords — conversion is locale-sensitive.

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Conversion-Rate Optimization (the product page)

Ranking gets the visit; these convert it. Order by impact:

1. First 1–3 screenshots — visible without scrolling. Lead with the #1 benefit as a captioned hero shot, not a bare UI screenshot. Use text overlays describing the value, not the feature name.
2. App icon — the single most-tested asset. High contrast, recognizable at 1× thumbnail size. (See app-brand-identity for icon craft.)
3. App preview video — autoplay (muted) at the top; first 3 seconds decide. Show the app in use, not a logo splash.
4. Title + subtitle — double duty: indexed and the first thing read. Make the subtitle a benefit, not a keyword dump.
5. Ratings & reviews — volume and recency feed both ranking and trust. Prompt for ratings with SKStoreReviewController/requestReview at a moment of delight (see storekit-purchases for the modern API).
6. Promotional text (170 chars) — editable without a review submission; use it for timely hooks (events, seasonal, "now with …").

Levers you can pull without an app update

• Promotional text and in-app events — edit anytime.
• Custom Product Pages (CPPs) — up to 35 variants with different screenshots/text for different ad campaigns; each has its own URL and conversion analytics.
• Product Page Optimization (PPO) — Apple's native A/B test for icon/screenshots/preview (up to 3 treatments vs baseline). Run one continuously.

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Audit Checklist (/aso-audit)

When auditing an existing listing, pull current metadata via asc-submission's asc_get_metadata / asc_get_app_info, then check:

• Title ≤ 30 chars, brand + 1 strong keyword, no wasted words.
• Subtitle ≤ 30 chars, benefit-driven, distinct keywords (no overlap with title).
• Keyword field = 100 chars used, no spaces, no repeats vs title/subtitle, no app/category name, no plurals-of-included-singulars.
• No keyword repeated across the three indexed fields.
• en-GB locale keywords filled (doubles English budget).
• Top revenue locales localized (keywords + subtitle + screenshots).
• First 3 screenshots are benefit-captioned, not bare UI.
• App preview video present, hooks in 3s.
• Promotional text used and current.
• PPO / Custom Product Pages in use for paid traffic.
• Ratings prompt wired to a delight moment, not app launch.

Report findings as: ✅ good / ⚠️ leaving value on the table / ❌ rule violation (e.g. keyword repetition, over-limit), each with the specific fix.

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The ASO Score Card (0–100)

For an audit, don't just list issues — score the listing so the user sees where they stand and what moves the needle most. Rate each factor 0–10, multiply by its weight, sum to 100.

#	Factor	Weight	What a 10 looks like
1	Title	15%	≤30 chars, brand + 1 high-value keyword, zero waste
2	Subtitle	12%	≤30 chars, benefit-led, distinct keywords (no title overlap)
3	Keyword field	12%	100/100 chars used, no spaces, no repeats, no app/category name
4	Localization coverage	12%	en-US + en-GB filled, all top-revenue locales localized
5	Screenshots (first 3)	13%	Benefit-captioned hero shots, not bare UI; hook in slot 1
6	App preview video	6%	Present, shows the app in use, hooks in 3s
7	Icon	8%	High contrast, legible at thumbnail, distinct from competitors
8	Ratings & reviews	10%	Healthy volume + recency; ≥4.5 avg; prompt at delight moment
9	Conversion levers	7%	Promo text current; PPO running; CPPs for paid traffic
10	Keyword relevance/targeting	5%	Ranking for terms the app genuinely satisfies, long-tail first

Score = Σ(factor ÷ 10 × weight). Report the number, the band (0–40 needs overhaul / 41–70 solid, leaking value / 71–100 optimized), and the three lowest-weighted-score factors as the priority fixes.

Tiered recommendations

After scoring, structure the output into three tiers so the user knows what to do today vs. this quarter:

• 🟢 Quick Wins — no-update, no-cost edits: keyword field rewrite, en-GB fill, promo text, subtitle tweak. Ship today.
• 🟡 High-Impact — needs an app/version update or asset work: screenshot redesign, preview video, icon test (PPO). Ship this cycle.
• 🔵 Strategic — sustained effort: full localization rollout, ratings-velocity program, CPP-per-campaign for Apple Search Ads (see apple-search-ads).

Competitor comparison

Discoverability is relative. Pull 2–3 direct competitors and compare side by side:

Field	You	Competitor A	Competitor B
Title keywords	…	…	…
Subtitle angle	…	…	…
Visible keyword themes	…	…	…
Rating (count / avg)	…	…	…
Screenshot hook	…	…	…

Use this to find the gap terms — relevant, lower-difficulty keywords competitors under-target — and the conversion ideas worth borrowing. Gather competitor metadata via WebSearch / the public App Store listing, or ask the user; for your own live fields use asc_get_metadata / asc_get_app_info.

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Measuring ASO

Use App Store Connect App Analytics:

• Impressions → Product Page Views → Downloads is the funnel. ASO discoverability moves impressions; CRO moves the views→downloads ratio (the conversion rate).
• Segment by Source Type: App Store Search (keyword ASO), App Store Browse (category/featuring), Web Referrer, App Referrer.
• Watch conversion rate per Custom Product Page and PPO treatment to pick winners.

A 1% absolute conversion-rate gain often beats weeks of ranking work — instrument both, optimize the cheaper one first.