iOS Keyword Field: The 100-Character Secret Most Indie Devs Ignore

There is a hidden field in App Store Connect that directly controls which search terms your app ranks for. It is invisible to users, takes two minutes to fill out, and most indie developers either leave it blank or waste it with formatting mistakes. The iOS keyword field gives you 100 characters of pure ranking power, and getting it right is one of the highest-leverage ASO moves you can make.

This guide covers the exact formatting rules Apple enforces, a character-by-character optimization strategy, and the mistakes that silently cost you downloads. If you are new to ASO, you may want to start with our complete App Store Optimization guide before diving in.

What the Keyword Field Is and Where to Find It in App Store Connect

The keyword field is a metadata field exclusive to iOS. It exists only inside App Store Connect, and no user browsing the App Store will ever see it. Apple uses it as a direct ranking signal -- every term you enter here becomes a search query your app can match against.

To find it, navigate to your app in App Store Connect, then go to the version you are editing. Under the localization section for each language, you will see a field labeled "Keywords" between the description and the support URL. It accepts up to 100 characters of comma-separated terms.

This field has no equivalent on Google Play. Android developers must embed keywords in their description because Google indexes the full description text. iOS developers have this dedicated, hidden field specifically for ranking purposes -- which makes it bizarre how many developers ignore it.

The keyword field works in combination with your title and subtitle. Apple indexes all three fields together and uses them to determine search relevance. This means the keyword field is not your only ranking input, but it is your largest single block of dedicated keyword space. Your title gives you 30 characters, your subtitle gives you 30, and the keyword field gives you 100. That is 100 characters of invisible real estate that exists purely to help Apple match your app to user searches.

Why Most Developers Waste Their 100 Characters

A surprising number of indie developers either leave the keyword field empty or fill it with obvious waste. Common patterns include repeating words already in the title, adding spaces after every comma, including articles and prepositions, or entering their own brand name -- all of which burn characters without adding a single new ranking term.

The cost is not abstract. Every wasted character in the keyword field is a keyword you are not ranking for. If you waste 30 characters on duplicates and formatting errors, that is roughly 5-7 additional keywords you could have targeted. Over the course of a year, those missing keywords translate directly into searches your app never appears in and downloads that go to competitors instead.

The reason this happens is simple: Apple provides no feedback. There is no warning when you duplicate a title word. There is no character efficiency score. You fill in the field, hit save, and Apple silently indexes whatever you gave it -- mistakes and all. Without understanding the rules, developers have no way of knowing they are leaving performance on the table.

The Formatting Rules You Must Follow

Comma-Separated, No Spaces After Commas

Apple expects keywords separated by commas with zero spaces between them. This is the single most common formatting mistake, and it is the easiest to fix.

The correct format:

budget,tracker,expense,money,saving,receipt,bill,wallet,planner

The incorrect format:

budget, tracker, expense, money, saving, receipt, bill, wallet

In the incorrect version, each space after a comma costs you one character. With 9 keywords, that is 8 wasted characters -- enough space for two additional short keywords. Over a full 100-character field, sloppy spacing can cost you 15-20 characters, which translates to 3-5 missed keywords.

Apple does not strip these spaces automatically. If you type budget, tracker, Apple indexes budget and tracker (with a leading space). Whether that leading space causes indexing issues is debated, but at minimum it wastes a character. Do not risk it. No spaces after commas, ever.

No Duplicates from Title or Subtitle

Apple indexes every word in your title and subtitle for search ranking. Repeating any of those words in the keyword field does not give you a ranking boost -- it simply wastes characters.

If your title is "BudgetPal - Expense Tracker" and your subtitle is "Simple Money Manager", Apple already indexes: budgetpal, expense, tracker, simple, money, manager. Putting any of those six words in your keyword field is pure waste.

This rule alone can free up 20-40 characters for developers who are currently duplicating. That is enough space for 4-8 entirely new keywords you were not ranking for before. The fix takes five minutes: list every word from your title, list every word from your subtitle, then remove all of them from your keyword field candidates.

No Plurals, No Articles, No Prepositions

Apple's search algorithm handles singular and plural forms automatically. If you include tracker, Apple will match searches for both "tracker" and "trackers." Including both forms wastes characters.

Similarly, strip out these word types -- Apple either ignores them or they add no ranking value:

• Articles: the, a, an
• Prepositions: for, with, in, on, to, by, of, at
• Conjunctions: and, or, but
• Common verbs: is, are, was, get, do

Every one of these words costs 2-4 characters and contributes nothing to your ranking. A keyword field that reads app,for,tracking,the,budget,and,saving has 18 characters of dead weight. Strip those filler words and replace them with actual keywords.

Character-by-Character Optimization Strategy

Think of your 100 characters as a budget. Every keyword has a cost (its character length plus one comma) and an expected return (search volume times your likelihood of ranking). The goal is to maximize total return within exactly 100 characters.

Start by building a candidate list of 30-40 keywords from competitor analysis, autocomplete research, and your own understanding of what users search for. If you need a structured process for building that list, our keyword research strategy guide walks through it step by step. For each candidate, note two things: how many characters it costs and how valuable it is.

Next, sort your candidates into tiers:

Tier 1 -- Must include (high volume, high relevance): These are non-negotiable. If a keyword has strong search volume and directly describes your app, it earns a spot regardless of length.

Tier 2 -- Strong candidates (moderate volume, high relevance): These fill the bulk of your field. Choose among them based on character efficiency -- a 4-letter keyword that ranks moderately beats a 12-letter keyword that ranks similarly.

Tier 3 -- Fill candidates (lower volume, still relevant): Use these to fill remaining characters. Often these are 3-5 character words that squeeze into the gaps.

Now build your field like a puzzle. Start with Tier 1 keywords, add Tier 2 until space gets tight, then fill remaining characters with the shortest Tier 3 options that fit. Count characters obsessively. Going even one character over 100 means Apple silently truncates your field, and you will not know which keywords got cut.

A practical tip: use a spreadsheet or text editor with character counting. Write your field in a single line, check the count, and adjust. Never enter keywords directly into App Store Connect without counting first.

What to Include vs. What to Exclude

Remove Your Brand Name

Unless your brand name is a common dictionary word that users might search generically, remove it from the keyword field. Your app name is already indexed from the title. The only exception is if users frequently misspell your brand -- in that case, including common misspellings can capture those searches.

For most indie apps, the brand name is not a search term. Nobody is searching "BudgetPal" until they already know your app exists. The keyword field should target discovery -- users who do not know your app and are searching for a solution to their problem. Every character spent on your brand name is a character not spent on reaching new users.

Remove Words Already in Title and Subtitle

This bears repeating because it is the most common waste. Here is the audit process:

1. Write out your full title. Circle every individual word.
2. Write out your full subtitle. Circle every individual word.
3. Look at your keyword field. Cross out every word that matches a circled word.
4. Count the freed characters. Fill them with new keywords.

Example: Title is "FitLog - Workout Tracker" and subtitle is "Exercise & Gym Logger." Words already indexed: fitlog, workout, tracker, exercise, gym, logger. If your keyword field contains workout,gym,tracker,fitness,health,routine,training,muscle, you are wasting 19 characters on three duplicates. Remove them and add diet,weight,cardio,reps instead.

Include Competitor Names (Carefully)

Apple does not explicitly prohibit competitor brand names in the keyword field, and ranking for competitor searches can drive significant traffic. However, there are important nuances.

Apple may reject your app update if trademarked terms trigger a review. Major brands like Nike, Spotify, or Peloton are risky. Smaller competitor names that are not globally trademarked are generally safer.

The character cost matters too. A competitor name like "MyFitnessPal" costs 12 characters -- enough space for three short keywords. Unless that competitor name drives substantial search volume, you are better off using the space for generic discovery terms.

If you do include competitor names, use the shortest recognizable form. And never include competitor names in your visible metadata (title, subtitle, description) -- that crosses into trademark territory and will get your app rejected.

Common Formatting Mistakes That Waste Characters

Here is a catalog of the most frequent errors, with the character cost of each:

The phrase mistake deserves special attention. When you write expense tracker as a single entry (with a space), Apple treats it as one phrase and matches it only to that exact query. When you write expense,tracker as two separate words, Apple can combine them to match "expense tracker," "expense manager," "budget tracker," and other permutations. Individual words give you combinatorial power; phrases lock you into a single match.

The only exception is when the phrase only makes sense as a unit. A term like "to do" might be worth keeping as a phrase because "to" and "do" separately are useless. But for most keyword pairs, split them.

How to Prioritize Keywords for Limited Space

Balancing Search Volume and Competition

A keyword with massive search volume but intense competition will not help you if your app sits on page 10 of results. Conversely, a keyword with zero competition but no search volume brings nobody to your listing.

For the keyword field specifically, lean toward moderate-volume, lower-competition keywords. Your title and subtitle already target your highest-volume terms. The keyword field is where you expand into the next tier -- terms that are relevant and searched but not dominated by apps with millions of reviews.

A quick validation method: search each keyword candidate in the App Store. If every result on the first page has over 100,000 reviews, the keyword is probably too competitive for your keyword field. If several results have under 10,000 reviews or seem loosely relevant, there is room for you to rank.

Short Words vs. Long Words Trade-Off

Character economics are real. A 3-character keyword like "fit" costs 4 characters (including its comma). A 12-character keyword like "bodybuilding" costs 13 characters. The long keyword needs to be roughly three times more valuable to justify the space it occupies.

Short, broad keywords have another advantage: they combine with other keywords to form more search matches. The word "fit" can combine with "tracker," "log," "plan," or "coach" to match multiple queries. The word "bodybuilding" is more specific but only matches one concept.

In practice, aim for an average keyword length of 5-7 characters. This gives you roughly 12-15 keywords in your 100 characters (accounting for commas). A field packed with 15 relevant keywords covers far more search queries than a field with 7 long ones.

Before and After Optimization Example

Consider a habit tracking app called "Streaks - Habit Tracker" with the subtitle "Build Better Daily Routines."

Before optimization (poorly formatted keyword field):

habit tracker, daily habits, routine, streaks, build habits for the new year, goal setting app

Character count: 89. But let's audit it:

• habit -- duplicated from title (waste: 5 chars)
• tracker -- duplicated from title (waste: 7 chars)
• daily -- duplicated from subtitle (waste: 5 chars)
• routine -- duplicated from subtitle (waste: 0, singular vs "routines" -- but Apple matches both, so waste: 7 chars)
• streaks -- brand name in title (waste: 7 chars)
• build -- duplicated from subtitle (waste: 5 chars)
• Spaces after commas -- 6 spaces (waste: 6 chars)
• for the new year -- prepositions and articles (waste: ~12 chars)
• app -- Apple indexes category (waste: 3 chars)

Total wasted: roughly 57 characters. Effective keywords added beyond title/subtitle: goal, setting, year. Three keywords from 89 characters. Terrible efficiency.

After optimization (properly formatted keyword field):

goals,morning,wellness,productivity,mindful,streak,challenge,remind,schedule,focus,discipline,log,plan

Character count: 100. Every term is unique, not in the title or subtitle, no spaces wasted, no articles, no duplicates. That is 13 keywords, each opening new search queries. Combined with title and subtitle words, this app now ranks for dozens of keyword combinations: "morning routine tracker," "productivity habit," "wellness goals," "daily challenge," "focus log," and many more.

The difference: 3 effective keywords versus 13. Same 100 characters. The only change was following the formatting rules.

How to Track Which Keywords Are Actually Ranking

Filling the keyword field correctly is half the job. The other half is verifying that your keywords are actually indexed and driving impressions.

Manual search testing: Open the App Store on a device (not the simulator) and search for each keyword you targeted. Note where your app appears. Do this within a week of your update going live -- Apple typically indexes new keywords within 24-48 hours but can take up to a week.

App Store Connect analytics: Check your Source > App Store Search metrics. If impressions increase after a keyword field change, the new terms are being indexed. You cannot see which specific keywords drive impressions in Connect, but the aggregate trend tells you whether your changes had impact.

Apple Search Ads: Even without running paid campaigns, the Search Ads keyword suggestions tool reveals which terms Apple associates with your app. If a term you added to your keyword field shows up in Search Ads suggestions, Apple is indexing it. This is the closest thing to a keyword ranking confirmation that Apple provides for free.

Iterate every 4-6 weeks: ASO is not a one-time task. After each measurement cycle, identify keywords that are not ranking despite being in your field (possibly too competitive) and replace them with new candidates. Over 3-4 cycles, you will converge on a keyword field that maximizes your actual search visibility rather than theoretical coverage.

Tools That Help with Keyword Field Optimization

StoreLit Keyword Analysis

StoreLit's ASO audit pulls real data from your competitors' App Store listings -- their titles, subtitles, descriptions, and the keywords they implicitly target. The keyword gap analysis shows you exactly which high-frequency terms competitors rank for that are missing from your listing. This directly informs your keyword field: the gap report is essentially a prioritized list of candidates to add.

The tool also flags duplicates between your title, subtitle, and keyword field, so you can spot wasted characters without manual auditing. For developers who want to optimize their keyword field based on actual competitive data rather than guesswork, it compresses hours of manual research into minutes.

Other Approaches

Apple Search Ads keyword tool: Free to access if you create a Search Ads account (no spend required). Enter your app and it suggests keywords with relative popularity scores. The scores are not precise, but they are directional -- a keyword with popularity 50 has meaningfully more volume than one with popularity 5.

Manual autocomplete testing: Type keyword candidates into the App Store search bar and observe autocomplete suggestions. If Apple suggests a term, it has real search volume. This is free, requires no tools, and gives you direct signal about what users actually search for.

Spreadsheet character counting: Open a spreadsheet, paste your keyword field in cell A1, and use =LEN(A1) to count characters. Build your keyword list in column B with character counts in column C, then use SUM to track your total as you add and remove terms. Low-tech but reliable.

Each approach has trade-offs. Search Ads gives you volume data but not competitive intelligence. Manual testing gives you real suggestions but is time-intensive. Spreadsheets help with formatting but not keyword discovery. The most effective workflow combines competitive data (from a tool like StoreLit or manual competitor analysis) with volume validation (from Search Ads or autocomplete) and character management (spreadsheet or text editor).

Key Takeaways

• The iOS keyword field is 100 characters of hidden ranking power. It exists only in App Store Connect and is invisible to users.
• Separate keywords with commas and no spaces. Every space after a comma wastes a character.
• Never duplicate words from your title or subtitle. Apple already indexes them.
• Strip plurals, articles, prepositions, and your brand name. None of them add ranking value.
• Use individual words, not phrases. Individual words combine to match more search queries.
• Prioritize moderate-volume, lower-competition keywords. Your title handles the high-volume terms.
• Aim for 12-15 keywords at 5-7 characters average length.
• Count characters before entering anything into App Store Connect. One character over means silent truncation.
• Track rankings after every update and iterate every 4-6 weeks.
• Once you have maxed out your 100 characters, use cross-localization to double your keyword coverage for free.

The keyword field is the most underoptimized metadata field in the entire App Store. Two minutes of formatting fixes and strategic keyword selection can meaningfully change how many searches your app appears in. There is no reason to leave this space underutilized.