guide · metadata · 5 min read
iOS Subtitle Strategy: The Highest-Leverage Metadata Field
Your 30-character subtitle is the strongest single metadata signal Apple ranks on. Here's how to choose what goes in it.
A 30-character field that punches above its weight
Apple indexes three text fields for App Store search ranking: the title (30 chars), the subtitle (30 chars), and the keyword field (100 chars). The description is not indexed on iOS — it is conversion copy that loads after Apple has already decided your rank. That leaves you a 160-character budget for ranking, and the subtitle is the only one of those three fields the user actually reads above the fold.
Apple Search Ads documentation describes the title as the highest-weighted ranking signal. A primary keyword in the title can shift a listing's rank by roughly 10%. But the title is also where your brand has to live. The subtitle is where the next-most weighted keyword should go — and unlike the title, it's easy to edit between releases.
The token-counted-once rule
Apple indexes the title, subtitle, and keyword field together and counts each token once. Repeating a keyword across two of these fields does not double the ranking weight — it wastes characters that could carry another term. In a sample Sniffy report, a productivity app spent two of its ten keyword-field slots on tokens already present in the subtitle, dragging its keyword sub-score from 70 down to 48.
The fix is mechanical: list each ranking term in exactly one place, and pick the place that maximizes both ranking weight (title > subtitle > keyword field) and user-visible intent (subtitle is the only one users read).
What to put in the subtitle
The subtitle should carry the highest-intent keyword that does not fit naturally into the title. "Highest intent" means the keyword is the actual query users type when they want the thing your app does. For a habit-tracking app, that is habit tracker — not daily routine, which has lower search volume and broader intent.
Apple's ranker prefers exact-phrase matches over scattered tokens. "habit tracker" as a contiguous phrase in the subtitle ranks higher than the same two words split across title and keyword field. If your subtitle is currently a marketing phrase like "Track your daily routine", you are spending a contiguous-phrase slot on a low-intent term.
How Sniffy measures this
Every paid Sniffy report includes a readyToPaste.subtitle field with a recommended rewrite and a changeReason explaining which keyword is being promoted and why. The recommendation is grounded in the report's keywordDiagnosis[] — we look at which terms are ranking 11–30 (worth pushing up) and which terms are unindexed but high-intent, then suggest a subtitle that surfaces one of them as an exact phrase.
The sample report shows the full output for a fictional habit-tracker app, including a flagged 4-character overage on a candidate subtitle — one of the things Sniffy will tell you that a hand audit usually misses.