I Rewrote 40 App Store Subtitles. Here's the Template That Performed.

I rewrote 40 App Store subtitles across nine categories last quarter. The six-word formula below out-converted every other shape we tried. Two patterns quietly killed conversion every time we tested them. The post documents both.

Composite reporting throughout. Apps are anonymised by category, not by name. The point is the template, not the leaderboard.

What we rewrote and how

Forty subtitles across nine categories: habit tracking, finance, meditation, language learning, sleep, fitness, journaling, invoicing, and one wildcard B2B niche. Each subtitle was tested against the prior subtitle on the same app under the same listing, screenshots unchanged, title unchanged. The only variable was the 30-character subtitle field.

Test window: 14 days per variant. Apple usually approves a metadata-only update inside 24 hours, so a 14-day test runs cleanly inside App Store Connect with the prior variant as the baseline.

The output metric was product-page conversion in App Store Connect. Not impressions. Not rank. Conversion of taps to installs on the product page, which is what the subtitle is actually doing.

The 6-word formula that performed

The pattern:

[keyword] + [verb] + [outcome] + [time or quantity hook]

Six words. Sometimes seven when the keyword is a compound noun. Always fits inside the 30-character subtitle limit. Three live examples from the rewrite set:

• Habit tracking. Streaks built in 60 seconds (28 chars). Keyword = Streaks, verb = built, outcome = (implicit completion), time hook = 60 seconds.
• Sleep. Sleep tracked, fixed in weeks (29 chars). Keyword = Sleep, verb = tracked / fixed, outcome = restored sleep, time hook = in weeks.
• Invoicing. Invoices paid 14 days faster (28 chars). Keyword = Invoices, verb = paid, outcome = faster payment, time hook = 14 days.

The shape is consistent. The keyword carries ranking weight. The verb commits. The outcome is concrete. The time-or-quantity hook gives the buyer a number to anchor to.

Anatomy of the formula

Why each component is in the formula:

Keyword first. Apple ranks the subtitle. The subtitle is the second-strongest ranking field after the title. Burning the first word on a tagline is the most common indie subtitle mistake. Front-load the keyword.

Verb second. A verb commits the subtitle to an action. "Smart sleep tracking" is a label. "Sleep tracked, fixed" is a promise. Apple does not care about the difference. The buyer does.

Outcome third. What changes for the buyer. Implicit when the verb completes the meaning ("built" implies completion). Explicit when the verb is open ("tracked, fixed" needs the outcome of restored sleep).

Time or quantity hook last. A specific number. 14 days, 60 seconds, 5 minutes a day, 1,000 reviews. The hook gives the buyer something to anchor expectations to. Vague subtitles read as risky. Specific subtitles read as accountable.

Two patterns that quietly killed conversion

Two anti-patterns showed up consistently in the original subtitles before rewriting:

The double tagline. "Best app for productivity. Loved by 1M users." Two micro-claims fighting for 30 characters. Each one diluted by the other. Conversion sat below the rewritten 6-word formula every time. The algorithm did not punish the double tagline. The buyer did.

The feature dump. "Goals, tasks, calendar, notes." A category list, four words, zero outcome. Buyers reading this learned what the app contains and nothing about why they should care. The dump pattern under-performed the 6-word formula by a wide margin every time we tested it.

Both anti-patterns are written from inside the app looking out. The 6-word formula is written from outside the app looking in. That is the structural difference.

Five example rewrites

Composite before-and-after across five of the nine categories. Apps anonymised to category-level.

Habit tracker. Before: Smart habits, smart life. After: Streaks built in 60 seconds. Lift: meaningful.

Finance. Before: Budget made simple. After: Spending fixed in two weeks. Lift: meaningful.

Meditation. Before: Calm starts here. After: Anxiety eased in 5 minutes. Lift: meaningful.

Language learning. Before: Languages, faster. After: Spanish learned in 20 days. Lift: meaningful.

Invoicing. Before: Invoicing for freelancers. After: Invoices paid 14 days faster. Lift: meaningful.

"Meaningful" deliberately stays unquantified here. The product-page conversion rates pulled from App Store Connect during the test window are owned by the participating apps, not by AsoGrove. Composite reporting keeps the apps anonymous and prevents anyone from reverse-engineering which listing changed.

Where the formula breaks

Three categories where the 6-word formula did not out-perform an alternative shape:

Strict utility apps with no outcome curve. Apps where the "outcome" is a single tap rather than a process (flashlight, unit converter, QR scanner). For these, a 4-word descriptor outperformed the 6-word formula. Verb + keyword + utility. Example: Scan QR codes instantly.

Branded category leaders. Apps whose brand name already carries the keyword (the app whose brand is the keyword itself). For these, the subtitle stops being a keyword field and becomes a positioning line. Different work, different post.

Highly localised storefronts. The 6-word formula works in English-first storefronts. In Japanese and Korean storefronts, the character economics change. The underlying logic (keyword, verb, outcome, hook) translates; the word count does not. Localise to a 4-clause structure, not a 6-word count.

Why we built AsoGrove around this

Subtitle rewriting is structural work that compounds. Once you have the formula, every new app uses it. Every rebrand uses it. Every seasonal refresh uses it.

AsoGrove's metadata generator runs the 6-word formula as one of its candidate subtitle shapes, pressure-tests it against the keyword density and character budget, and outputs five candidate subtitles ranked by ranking-signal score. You pick the strongest. Time to rewrite a subtitle drops from an hour to about 90 seconds per app.

Pair the subtitle rewrite with App Store Keyword Research in 60 Seconds for the keyword work and App Store Screenshots That Convert for the visual side. The subtitle is one lever in a system, not a standalone fix.

The template, summarised

1. Keyword first.
2. Verb second.
3. Outcome third.
4. Time or quantity hook last.
5. Six words. Sometimes seven. Fits inside 30 characters.
6. Avoid the double tagline. Avoid the feature dump.
7. Re-test every 90 days against new competitor subtitles in your category.

Boring, structural, compounding. Same as the rest of indie ASO.

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