App Store Title, Subtitle, and Keyword Field: What Goes Where

The App Store gives you three indexed text fields and 160 characters in total: an app name of at most 30 characters, a subtitle of at most 30, and a keyword field of 100. Your single strongest term goes in the name, your strongest non-overlapping term goes in the subtitle, and everything else goes in the keyword field, comma-separated, with no spaces and no word repeated from the other two.

That is the whole answer. The rest of this article is the detail that makes it survivable in practice: Apple's exact limits and where they are documented, the restrictions Apple places on what you may put in each field, which fields you can change without shipping a new version, and how to turn a keyword shortlist into three concrete field assignments. Every limit below is quoted from Apple's own documentation rather than from ASO convention, because this is one of the areas where third-party sources have quietly drifted from the source.

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The Short Answer

• Name: 2–30 characters. Apple: the name "must be at least two characters and no more than 30 characters."
• Subtitle: 30 characters. Apple: it "can't be longer than 30 characters."
• Keywords: 100 characters, comma-separated, no spaces after the commas. Spaces count against the limit.
• Never repeat a word across fields. Apple lists duplicate words among the things not to use in the keyword field. Repetition buys nothing and costs characters.
• Promotional text (170 characters) is the only one you can change anytime. Name, subtitle and keywords ship with a version.
• The description is not on Apple's list of indexed fields. Write it for humans.

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The Three Fields, With Apple's Own Numbers

Field	Limit	Apple's wording	Changeable without a new version?
App name	2–30 characters	"The name must be at least two characters and no more than 30 characters."	No
Subtitle	30 characters	"This can't be longer than 30 characters."	No
Keywords	100 characters	"Limited to 100 characters total, terms separated by commas and no spaces"	No
Promotional text	170 characters	"You can update promotional text at any time without having to submit a new version of your app"	Yes
Description	Long-form	"You can update your app's description when you submit a new version of your app"	No

Sources: Apple, App Store Connect Help — App information and App Store Product Page. The 30-character name limit is restated in App Review Guideline 2.3.7: "App names must be limited to 30 characters."

Two things follow immediately from that table.

Your ranking metadata is version-locked. Name, subtitle and keywords cannot be edited on a live app without submitting a new version and passing review. This is the single most important operational fact about App Store metadata, and it is why keyword research deserves more care than pricing — which, as covered in how to price an iOS app, you can change at any time without a release.

Promotional text is your only fast lever, and it is not a ranking one. Apple's stated text-relevance matches are the title, subtitle, keywords and primary category. Promotional text is not among them. It is a conversion and announcement surface — a sale, a new feature, a seasonal message — that you can swap in an afternoon.

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What Apple Says It Matches On

Before assigning anything, it is worth re-reading the sentence that governs the whole exercise. From Apple's App Store search page:

"Search results are based on a number of factors, including text relevance (matches for your app's title, subtitle, keywords, and primary category), as well as user behavior (downloads, ratings and reviews, and more)."

Four text fields. Three of them are the ones in this article; the fourth is your primary category, which most developers never think of as a keyword decision at all. If your app is a meditation timer, your category selection is participating in text matching alongside your subtitle.

What that sentence does not contain is the description or the promotional text. Advice that tells you to weave keywords through your description is going beyond Apple's documentation. It is not necessarily wrong — Apple has not stated the description is ignored — but you should know you are acting on inference, and you should not spend your best terms there.

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What You May Not Put In These Fields

Apple constrains content as well as length, and the constraints are enforced at review. From Guideline 2.3.7:

"Choose a unique app name, assign keywords that accurately describe your app, and don't try to pack any of your metadata with trademarked terms, popular app names, pricing information, or other irrelevant phrases just to game the system. App names must be limited to 30 characters. Metadata such as app names, subtitles, screenshots, and previews should not include prices, terms, or descriptions that are not specific to the metadata type. App subtitles are a great way to provide additional context for your app; they must follow our standard metadata rules and should not include inappropriate content, reference other apps, or make unverifiable product claims. Apple may modify inappropriate keywords at any time or take other appropriate steps to prevent abuse."

Apple's product page guidance adds a specific do-not-use list for the keyword field: no plurals, no category names, no the word "app," no duplicate words, no unauthorised trademarked terms, no celebrity names, no competing app names, and nothing irrelevant or inappropriate.

Read as a working checklist:

Rule	Consequence if ignored
No competitor or trademarked names	Rejection, keyword modification, or removal
No prices anywhere in name, subtitle, screenshots or previews	Rejection under 2.3.7
No unverifiable claims in the subtitle ("the best," "#1")	Rejection
No duplicate words across fields	Wasted characters from a 100-character budget
No plurals	Wasted characters
No category names, no "app"	Wasted characters
Keywords must accurately describe the app	Apple may modify them itself

The last line in Apple's guideline is the one people underestimate. Apple reserves the right to "modify inappropriate keywords at any time." Your keyword field is not a private input you control unilaterally.

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How the Keyword Field Works — Documented vs. Assumed

This is where it pays to separate what Apple states from what the ASO field has settled on by observation. Getting this boundary right is worth more than any specific tactic.

Documented by Apple:

• The field holds 100 characters.
• Terms are separated by commas, with no spaces.
• Certain content is disallowed (the list above).
• Keywords are one of four text-relevance matches for search.

Not documented by Apple — widely assumed, and treated as true by practitioners:

• That the store combines individual words across your name, subtitle and keyword field into multi-word phrases, so "focus" in your title and "timer" in your keywords can together match "focus timer."
• That singulars and plurals are handled well enough that supplying both is wasteful.
• That word order within the keyword field carries no weight.

The reason to state that boundary plainly is practical: the assumed behaviours are what make "never repeat a word" a rule rather than a preference. If cross-field combination did not happen, duplication would merely be inefficient instead of pointless. Apple's own instruction not to use duplicate words is consistent with the assumption, which is the strongest confirmation available — but it is not a published description of the matching algorithm, and no third-party tool has one either.

The safe operating rule: treat your name, subtitle and keyword field as one shared 160-character vocabulary with no repeats. That behaves correctly whether or not cross-field combination works exactly as the field believes.

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Assigning Your Shortlist to the Three Fields

Assume you have come out of the keyword research guide with a shortlist of ten to fifteen terms, sorted by a rough sense of volume and winnability. Here is how they map.

The name: one head term, plus your brand

The name does two jobs that pull against each other. It carries your strongest keyword, and it is how people recognise and recommend you. Thirty characters is not much room for both.

The convention that works is Brand — Descriptor, where the descriptor is your single most important term:

• Lumen — Focus Timer (19 characters)
• Sift — Expense Tracker (22)
• Tidewatch — Surf Forecast (25)

Two failure modes to avoid. A bare brand name — Lumen — spends the most heavily weighted field on a word nobody searches for until you have a brand worth searching. And a keyword pile — Focus Timer Study Pomodoro Work Timer — is over the limit, unreadable in the results list where the name is truncated, and reads to a reviewer exactly like the packing Guideline 2.3.7 prohibits.

Use fewer characters than the maximum if the natural name is shorter. There is no bonus for filling the field, and long names get truncated on the search results row.

The subtitle: one strong mid-tail term, no repeats

Thirty characters, appearing directly under the name everywhere in the store. It is simultaneously your second ranking field and the line that tells a scanning user what the app does.

Pick the strongest term on your shortlist that shares no word with the name:

• Name Lumen — Focus Timer, subtitle Pomodoro study sessions (23 characters). No repeated word, adds three new indexed terms, and reads as a sentence fragment a human understands.
• Name Sift — Expense Tracker, subtitle Budget planner & receipts (25). Again, no overlap.

Do not spend the subtitle on a value claim. The best way to stay focused uses all thirty characters, indexes nothing useful, and risks Guideline 2.3.7's prohibition on unverifiable product claims.

The keyword field: everything else, packed tight

One hundred characters, invisible to users, comma-separated with no spaces. This is where the long tail goes.

Rules that follow directly from Apple's guidance:

1. No spaces after commas. Every space is a character you are not spending on a word.
2. No word already used in your name or subtitle.
3. Singular only. Plurals are on Apple's do-not-use list.
4. No "app," no category names.
5. Single words, not phrases, on the assumption that the store recombines them. Writing study timer and focus timer spends timer twice.

Worked example for the focus timer app, given a name of Lumen — Focus Timer and a subtitle of Pomodoro study sessions:

deep,work,concentration,productivity,break,interval,tomato,reminder,schedule,routine

That is 83 characters. Every word is new — none appears in the name or subtitle — and each one can combine with the terms already indexed there. The remaining 17 characters are worth spending on two or three more distinct words rather than left blank.

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The Field-by-Field Checklist

Before you submit:

• App name is between 2 and 30 characters, contains your single strongest term, and reads as a name
• Subtitle is 30 characters or fewer and shares no word with the name
• Subtitle contains no superlatives, no competitor references, and no price
• Keyword field is at or near 100 characters with no spaces after commas
• No word appears in more than one of the three fields
• No plurals, no "app," no category names, no trademarks, no competitor names in the keyword field
• No price or promotional term appears in the name, subtitle, screenshots or previews
• Primary category is the one your app genuinely belongs in — it is a text-relevance match, not just a filing decision
• Promotional text is written and ready, since it is the only one of these you can change afterwards without a release

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Check Who You Are Competing With Before You Commit

Field assignment is only as good as the shortlist feeding it, and the part of a shortlist you cannot judge by reading the store is how big the incumbents on each term actually are.

App Store Operator is a free, open-source MCP server that puts App Store competitive data inside Claude — search rankings plus estimated monthly downloads, estimated monthly revenue, rating count, rating score, publisher country and top markets. Register it with one command:

claude mcp add --transport stdio app-store-operator -- npx -y app-store-operator@latest

Then check a candidate term before you spend a field on it:

Research the top rivals for "pomodoro timer" in the US App Store, and show me each app's name and subtitle alongside its download and rating numbers.

Reading the top apps' names and subtitles next to their actual size is the fastest way to see which terms are defended and which are merely occupied. Two of the four tools — search_app_store and prepare_iae — need no account at all. The two analytics tools, research_rivals and get_app_details, open a browser window once for a one-time sign-in to a free SensorTower account, then reuse that saved session locally. The use cases page has the exact prompts.

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Frequently Asked Questions

What is the character limit for an App Store app name?

Apple states the app name "must be at least two characters and no more than 30 characters." App Review Guideline 2.3.7 restates the maximum: "App names must be limited to 30 characters." The limit counts every character including spaces and punctuation, and names longer than roughly 20 characters are frequently truncated in App Store search results rows.

How many characters is the App Store subtitle?

Thirty. Apple's App Store Connect documentation states the subtitle "can't be longer than 30 characters." It appears under your app name across the App Store, and it is one of the four text fields Apple names as a search text-relevance match.

How many characters is the App Store keyword field?

One hundred characters total, with terms separated by commas and no spaces. Spaces count toward the limit, which is why the convention is to omit them after commas. The field is not visible to users.

Should I repeat my main keyword in the title, subtitle, and keyword field?

No. Apple's own keyword guidance lists duplicate words among the things not to use, and practitioners assume the store combines words across the three fields, so a repeated word gains nothing while consuming characters from a 100-character budget. Treat the three fields as one shared vocabulary and use each word once.

Can I change my App Store keywords without releasing a new version?

No. The app name, subtitle and keyword field are all version-locked — changing them requires submitting a new app version and passing review. The only metadata field Apple lets you change at any time without a new version is promotional text, which is limited to 170 characters and is not one of the fields Apple names as a search text-relevance match.

Do App Store keywords need to be single words or phrases?

Practitioners use single words, on the assumption that the store recombines words across your name, subtitle and keyword field into multi-word matches. Apple documents the format — comma-separated, no spaces — and the content restrictions, but it does not publish how terms are combined. Single words are the safer default because they avoid spending a scarce character budget on a word you have already supplied.

Does the App Store index my app description?

Apple names the title, subtitle, keywords and primary category as its text-relevance matches for App Store search. The description is not on that list. Apple has not stated that the description is ignored, so the honest position is that keyword-loading it is unsupported by Apple's documentation — and Apple separately advises against including "unnecessary keywords for search manipulation" in the description.

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Get the Order Right

The sequence that works is research, then assignment, then submission — and only the last step is reversible on a schedule you control. Because name, subtitle and keywords ship with a version, a rushed assignment is locked in for as long as your release cadence says it is.

So spend the time upstream. What is App Store Optimization covers what these fields are actually doing in the ranking system, the keyword research guide builds the shortlist, and the competition analysis framework tells you whether the term at the top of that shortlist is one you can win at all.

When you are ready to pull the competitive numbers:

claude mcp add --transport stdio app-store-operator -- npx -y app-store-operator@latest

npx app-store-operator@latest