If your subtitle says “Budget Tracker, Finance App” and your keyword field contains “budget tracker,finance,expense app,” you just threw away 26 characters.
Apple does not reward duplication. It ignores it.
When Apple’s algorithm indexes your metadata, it reads your title, subtitle, and keyword field as a single pool of indexable terms. If a word appears in the title and again in the keyword field, Apple indexes it once. The second instance earns no additional ranking weight and costs you character budget that could have targeted a completely different keyword.
This is one of the most common and most expensive ASO mistakes indie developers make. Not because it is hard to understand, but because nobody told them the rule.
How Apple indexes your metadata fields
You have three indexable text fields in iOS metadata:
- App name (title): 30 characters, highest ranking weight
- Subtitle: 30 characters, second-highest ranking weight
- Keyword field: 100 characters, lower weight but your broadest coverage surface
Apple reads all three fields together and constructs a keyword index for your app. The signal from each field is weighted differently: title carries the most ranking authority, subtitle is second, and the keyword field the least. The critical behavior is this: if the same term appears in more than one field, Apple indexes it once at the weight of the highest-ranking field it appears in.
What that means in practice: any character you spend repeating a title keyword in your subtitle, or a subtitle keyword in your keyword field, produces zero incremental ranking benefit.
You are paying the character cost twice and getting the index benefit once.
What duplication actually costs you
Consider a productivity app with this metadata:
- Title: “FocusBlock: Distraction Blocker”
- Subtitle: “Distraction Blocker for iPhone”
- Keyword field: “distraction,focus app,productivity timer,blocker,focus mode”
Every instance of “distraction” and “blocker” past the title is wasted. Those 30 characters of subtitle could be covering entirely different search terms.
A 100-character keyword field is not a lot of space. Repeating words already indexed from your title or subtitle eats into it fast. If you are targeting five to eight keywords, losing 20 or 30 characters to duplication means one or two keywords simply do not get coverage.
The average indie app wastes between 20 and 40 characters of keyword field budget on terms that already appear in its title or subtitle. That is a structural inefficiency that no amount of keyword research can fix, because the problem is not which keywords you picked, but that some of your character budget is doing nothing.
How to audit your current metadata
Run this check before your next metadata update:
- Write out your current title, subtitle, and keyword field.
- Highlight every word that appears in more than one field. Ignore articles and prepositions.
- Count the characters consumed by duplicates in your keyword field.
- Replace every duplicate with a non-overlapping term that targets a distinct search query.
A clean metadata set has zero overlap between fields. Every character in your keyword field targets a term that does not appear in your title or subtitle.
This is a one-time audit with compounding returns. Once you clear the duplication, each future keyword update starts from a clean baseline where your full character budget is working.
What to do instead
The goal is maximum non-overlapping keyword coverage across all three fields.
Title: Choose your single most important keyword bet: one with high enough volume to matter and low enough competition that you can realistically rank in the top 15. This keyword should not appear anywhere else in your metadata.
Subtitle: Choose your second-best keyword bet or a phrase that describes a different user need. It should complement the title keyword, not repeat it. “Budget Tracker” in the title and “Expense Reports, Receipt Scanner” in the subtitle covers three distinct search intents. “Budget Tracker” in the title and “Best Budget Tracker App” in the subtitle covers one.
Keyword field: Use this space for terms that are not in your title or subtitle. Think of it as an expansion layer. Every term here is net new coverage, not reinforcement of what you have already indexed.
The subtitle-keyword field relationship is where most developers leave the most opportunity on the table. A 30-character subtitle targeted at a different search intent than the title, combined with a 100-character keyword field with zero overlaps, gives you 160 unique characters of coverage. Most apps running duplicated metadata are working with 100 or fewer.
The duplication most developers miss
Beyond obvious repetition, there is a subtler form of duplication that is easier to overlook: word stems.
If your title contains “track,” adding “tracking,” “tracker,” and “tracked” to your keyword field is largely redundant. Apple’s indexing handles stemming: it treats morphological variants of the same root as related. Filling your keyword field with stem variations of title words is a version of the same waste.
Similarly, if a keyword phrase appears in your title, its component words do not add coverage in the keyword field. “Expense Tracker” in your title means “expense” and “tracker” individually in the keyword field add nothing.
The practical takeaway: treat your keyword field as a list of concepts, not a list of words. Each concept should address a search query that is categorically different from what your title and subtitle already cover.
Checking your work against competitors
One useful calibration: look at what your top-ranking competitors do not repeat across their fields.
Apps with strong keyword footprints tend to have diverse, non-overlapping metadata. Their titles, subtitles, and keyword fields each target different queries. When you see a competitor ranking for 20 distinct terms with a 30-character title and a 100-character keyword field, the math only works if they are not wasting characters on repetition.
Marteso’s competitor tracking surfaces the keywords competitors rank for alongside your own. When you compare their metadata to their keyword footprint, duplication gaps become visible fast. If a competitor ranks for 15 terms you do not, and their metadata is tight, that is a signal about how they are allocating character budget, not just which terms they chose.
How Marteso catches this
Marteso’s AI Keyword Discovery evaluates your metadata fields together and flags duplicate coverage. When you run a keyword suggestion, the output filters out terms that already appear in your indexed fields and surfaces gap keywords (terms your app does not currently rank for that match your category and competitor footprint).
This means you can audit your live metadata inside Marteso, see exactly where your character budget is going, and get a ranked list of replacement keywords in the same workflow.
The 21-day ASO loop is built on incremental, measurable changes. Clearing keyword duplication is one of the fastest structural improvements you can make before the next test, because it gives every future keyword bet a cleaner signal with more room to expand.
Your keyword field has 100 characters. Make all 100 of them count.