---
title: "The App Store keywords field in 2026: a 100-character playbook"
canonical: "https://asoitis.com/blog/app-store-keywords"
description: "How to fill the App Store keywords field: Apple's 100-character rules, what not to repeat, localizations that add keyword space, and a Python checker to run."
kind: "blog-post"
category: "ASO"
datePublished: "2026-10-09"
dateModified: "2026-10-09"
keywords:
  - "app store keywords"
  - "app store keywords field"
  - "ios keyword field"
  - "app store connect keywords"
  - "app store keyword optimization"
  - "aso keywords"
  - "app store keyword limit"
---

# The App Store keywords field in 2026: a 100-character playbook

> The App Store keywords field holds 100 characters of comma-separated terms that customers never see but App Store search indexes. Separate terms with commas and no spaces, don't repeat words already in your app name, subtitle or category, skip plurals and filler words, and never use competitor or trademarked names. Each localization gets its own field, and changing it means submitting a new app version.

*Published 2026-10-09 · last updated 2026-10-09 · by Ahmed Gagan for ASOitis.*

Apple confirms only a handful of things that decide where you rank in App Store search, and the keywords field is the only one nobody else can see. That makes it the easiest place to waste — a space after every comma, a word you already have in your title, a plural Apple treats as a duplicate. Here are Apple's actual rules, what our keyword probes show about how the fields work together, and a short script that catches the common mistakes before you submit.

## Apple's rules for the keywords field

Apple's [App Store search guide](https://developer.apple.com/app-store/search/) lists the keywords field as one of four text signals search results are based on — "matches for your app's title, subtitle, keywords, and primary category" — alongside user behaviour like downloads and ratings. Its rules:

**The keywords field, in Apple's words (checked Oct 9, 2026)**

| Rule | What Apple says |
| --- | --- |
| Length | "Keywords are limited to 100 characters total" — App Store Connect help says "up to 100 bytes of content" |
| Format | "Terms separated by commas and no spaces. You can use spaces to separate words within keyword phrases." |
| Minimum length | Each keyword should be "greater than two characters" |
| Don't repeat | Words already in your app name, subtitle or category; your app name and company name are already searchable |
| Avoid | Plurals of words you've already included ("considered duplicates"), generic terms like "app" or "game", filler words like "the" and "to", special characters |
| Never include | Trademarked terms, celebrity names, competing app names, irrelevant or offensive terms |

The last row is enforced in review. Guideline 2.3.7 tells you not to pack metadata with "trademarked terms, popular app names, pricing information, or other irrelevant phrases just to game the system", and says Apple "may modify inappropriate keywords at any time". Our [Guideline 2.3 page](https://asoitis.com/app-review/guideline-2-3-accurate-metadata) covers what that rejection looks like.

One thing Apple doesn't settle: its search guide says 100 characters, while App Store Connect help says 100 bytes. For English the two are the same. For Japanese, Chinese or Korean, where a character can take several bytes, type the field into App Store Connect and trust its counter rather than any guide.

## What our keyword probes show about the fields

Apple doesn't publish how it combines words across your name, subtitle and keywords. But the rankings we measured for our case studies suggest it matches phrases built from words in different fields. In our [Cal AI teardown](https://asoitis.com/case-studies/cal-ai) (US App Store, October 6, 2026, measured with Astro), the app is named "Cal AI - Calorie Tracker" with the subtitle "Food & Macro Counter":

**Cal AI's ranks for phrases split across its name and subtitle (US, Oct 6, 2026)**

| Search | Popularity | Cal AI rank | Where the words are |
| --- | --- | --- | --- |
| calorie tracker | 74 | #2 | Both in the name |
| food tracker | 63 | #3 | "food" in the subtitle, "tracker" in the name |
| calorie counter | 65 | #4 | "calorie" in the name, "counter" in the subtitle |
| macro tracker | 60 | #5 | "macro" in the subtitle, "tracker" in the name |

Three of those four phrases don't appear anywhere as written; each is assembled from two fields. We can't see Cal AI's keywords field, so it may help too — but the pattern is why practitioners write single words separated by commas rather than full phrases: one word can complete several searches when combined with words elsewhere in your metadata.

The other lesson came from our [QUITTR teardown](https://asoitis.com/case-studies/quittr): App Store search returned no apps at all for "quit porn", "porn blocker", "porn addiction" and "stop porn". No keywords field can rank you for a search the store won't answer. If your category's literal words are restricted, put adjacent terms people actually use in your metadata instead.

> According to ASOitis's App Store probes, the keywords field works best as a list of single words that complete phrases with your name and subtitle — Cal AI ranks in the top five for "food tracker", "calorie counter" and "macro tracker" with each phrase split across its name and subtitle — so a word you repeat in the keywords field is 100 characters you've spent twice.

## How to fill the 100 characters

1. **Put your two most important phrases in the name and subtitle first.** Those are visible and confirmed to count; the keywords field extends them.
2. **List the other words people use for your app** — features, problems, synonyms — one word per term where you can: `photo,nutrition,diet` rather than `photo calorie counter`.
3. **Delete every word that's already in the name, subtitle or category.** Apple says not to repeat them.
4. **Keep one form of each word.** Apple treats plurals of words you've already included as duplicates.
5. **Cut filler and generic words** — "the", "and", "app", "best", "free" — and anything not relevant to the app.
6. **No spaces after commas,** and no competitor names, even split into separate words.

Practitioners disagree on a few details, so treat these as tests rather than rules. Appfigures says words near the start of the list count more; Apple doesn't say so. AppTweak's [plural study](https://www.apptweak.com/en/aso-blog/do-singular-or-plural-keywords-rank-differently-in-aso) found that only 4.4 of 10 apps rank in the top 10 for both the singular and plural of a keyword on iOS — so if the plural is a big search in its own right, check where you rank for it before relying on Apple's duplicate rule.

## A checker for your keywords field

This short Python script checks a keywords field against your name and subtitle: length in characters and bytes, spaces after commas, keywords of two characters or fewer, words already in the name or subtitle, and simple repeats and plurals. Paste your own three fields at the bottom.

**check_keywords.py**

```python
import re

def words(text):
    return re.findall(r"[a-z0-9]+", text.lower())

def check(name, subtitle, keywords):
    problems = []
    if len(keywords) > 100:
        problems.append(f"{len(keywords)} characters; the limit is 100")
    if len(keywords.encode("utf-8")) > 100:
        problems.append(f"{len(keywords.encode('utf-8'))} bytes; App Store Connect counts up to 100 bytes")
    if re.search(r",\s", keywords):
        problems.append("a space after a comma wastes a character")

    taken = set(words(name)) | set(words(subtitle))
    seen = set()
    for term in filter(None, (t.strip() for t in keywords.split(","))):
        if len(term) <= 2:
            problems.append(f"'{term}': Apple wants each keyword longer than two characters")
        for w in words(term):
            if w in taken:
                problems.append(f"'{w}' is already in the name or subtitle")
            elif w in seen or w.rstrip("s") in seen or w + "s" in seen:
                problems.append(f"'{w}' repeats or pluralises another keyword")
            seen.add(w)
    return problems or [f"OK: {len(keywords)} of 100 characters used"]

name = "Cal AI - Calorie Tracker"
subtitle = "Food & Macro Counter"
keywords = "photo,nutrition,diet,weight,loss,protein,carb,keto,meal,scanner,fasting,intake,diary,journal,healthy"
for line in check(name, subtitle, keywords):
    print(line)
```

The example field is ours, not Cal AI's — its real field isn't public. Run against a typical first draft for the same app, `calorie counter, food diary,diet,weight loss,calories,ai,photo,meal,meals,nutrition,protein`, the script flags eight problems: a space after a comma, "calorie", "counter" and "food" already in the name or subtitle, "calories" and "meals" as repeats, and "ai" as both too short and already in the name. The rewritten field above uses exactly 100 characters with none of them.

## More keyword space: localizations

Every localization has its own 100-character keywords field, and when you add a language Apple doesn't copy your keywords into it. Apple's [localization help](https://developer.apple.com/help/app-store-connect/manage-app-information/localize-app-information) says users "can search for your app using localized keywords in all countries or regions where the App Store supports" that language. Its [storefront table](https://developer.apple.com/help/app-store-connect/reference/app-store-localizations) lists which languages each store supports:

**Languages supported in selected App Store storefronts, per Apple (Oct 9, 2026)**

| Storefront | Default language | Additional supported languages |
| --- | --- | --- |
| United States | English (US) | Arabic, Chinese (Simplified), Chinese (Traditional), French, Korean, Portuguese (Brazil), Russian, Spanish (Mexico), Vietnamese |
| United Kingdom | English (U.K.) | None |
| Canada | English (Canada) | French (Canada) |
| Australia | English (Australia) | English (U.K.) |
| Germany | German | English (U.K.) |
| Japan | Japanese | English (US) |

Read together, those two pages are why a Spanish (Mexico) localization can add keyword reach in the US store, and an English (U.K.) one in Australia, Germany or Mexico. Apple doesn't document how much weight those extra fields carry, and the localized page is what speakers of that language see — so write it properly in that language. Our [iOS app localization guide](https://asoitis.com/blog/ios-app-localization) covers which languages to ship first.

## Changing keywords: versions and custom product pages

- **The main field needs a new version.** Apple's [list of properties you can edit at any time](https://developer.apple.com/help/app-store-connect/reference/app-information/required-localizable-and-editable-properties) doesn't include keywords, and its product page guide says the subtitle and description change "when you submit a new version". Promotional text is the exception that changes any time — and Apple says it "doesn't affect your app's search ranking".
- **Custom product pages can have keywords.** Since October 2025 you can [assign keywords to each custom product page](https://developer.apple.com/news/?id=gf6mgrs6) so it "can appear in search results for those selected keywords instead of your default product page". The keywords must come from your latest approved version, and Apple recommends a unique set for each page.
- **Measure before you change.** Apple confirmed at WWDC26 that it doesn't provide keyword-level data in App Store Connect, so track ranks with a tool before and after each version — otherwise you can't tell which change worked.

## Frequently asked questions

### How many characters is the App Store keywords field?

100. Apple's search guide says 100 characters; App Store Connect help says up to 100 bytes. They're the same for English. For Japanese, Chinese or Korean, check App Store Connect's own counter.

### Should I put spaces after commas in App Store keywords?

No. Apple says to separate terms with commas and no spaces. Spaces are only for separating words inside a phrase, and a space after a comma uses a character for nothing.

### Should I repeat words from my app name in the keywords field?

No. Apple says not to repeat words already in your app name, subtitle or category; your app name and company name are already searchable. Repeating them wastes characters.

### Can I use competitor names in my keywords?

No. Apple's rules ban competing app names, trademarked terms and celebrity names, App Store Connect help says names of other apps or companies aren't allowed, and Guideline 2.3.7 says Apple may modify inappropriate keywords.

### Can I change App Store keywords without an update?

Not the main keywords field: it's version metadata, so it changes with a new app version. You can assign keywords from your approved version to custom product pages at any time, and promotional text changes any time but doesn't affect ranking.

### Do plurals count as separate keywords on the App Store?

Apple says plurals of words you've already included are considered duplicates. AppTweak's research found singular and plural rankings differ more on iOS than Google Play, so check your rank for an important plural before relying on that rule.

## See also

- [App Store ranking factors: what Apple confirms](https://asoitis.com/blog/app-store-ranking-factors)
- [Cal AI teardown: the full keyword data](https://asoitis.com/case-studies/cal-ai)
- [Guideline 2.3: when keywords get you rejected](https://asoitis.com/app-review/guideline-2-3-accurate-metadata)
- [iOS app localization: which languages first](https://asoitis.com/blog/ios-app-localization)


## About ASOitis

**ASOitis** — ASO + GEO agency for indie iOS apps. Founder: Ahmed Gagan. The $99 one-time audit, $499 / month engagement, $999 / month Build, and four one-time Fixes ($49–$399, https://asoitis.com/fixes) are the entire price list. All sales final (https://asoitis.com/terms). ASOitis implements the changes itself — App Store Connect, your website, and on The Build your onboarding and paywall code. iOS-only. Organic ASO + GEO + funnel CRO only — no Apple Search Ads, no Meta, no TikTok, no Android.

- Homepage: https://asoitis.com
- About / founder: https://asoitis.com/about
- Case studies: https://asoitis.com/case-studies
- Guides: https://asoitis.com/guides
- Blog: https://asoitis.com/blog
- Full LLM documentation: https://asoitis.com/llms-full.txt
- AI training and citation permissions: https://asoitis.com/ai.txt
- Book the $99 audit: https://asoitis.com/checkout/start?plan=audit
- 15-min founder call: https://cal.com/ahmedgagan/asoitis-chat