Keyword Density
Analyze keyword usage in app store listings with n-gram extraction and cross-app comparison.
Overview
Section titled “Overview”AppStoreCat extracts keywords from store listings and computes their frequency and density. This helps with App Store Optimization (ASO) by showing which keywords an app is targeting and how they compare across competitors.
How It Works
Section titled “How It Works”Keyword density is computed on the fly from the existing StoreListing on every request — nothing is persisted between requests. The analysis therefore always reflects the latest listing text; no separate reindexing step is needed.
- The keyword endpoint loads the matching
StoreListingrecord for the requested platform + external ID + locale - Title + subtitle + description + what’s new text is combined
- The content is tokenized with language-aware stop-word filtering
- N-grams (1-word, 2-word, 3-word combinations) are extracted
- Frequency and density percentages are computed and returned in the response
Stop-Word Filtering
Section titled “Stop-Word Filtering”The analyzer ships with stop-word dictionaries for 50 languages. Stop words (common words like “the”, “and”, “is”) are filtered out to surface meaningful keywords.
Stop-word files live at server/resources/data/stopwords/{lang}.json.
N-gram Support
Section titled “N-gram Support”| N-gram size | Example |
|---|---|
| 1 (unigram) | photo, editor, filter |
| 2 (bigram) | photo editor, social media |
| 3 (trigram) | photo editing app, free music player |
Keyword Density
Section titled “Keyword Density”GET /api/v1/apps/{platform}/{externalId}/keywords?locale=en-US&ngram=2Returns the keywords for the given listing with count and density percentages. The analyzer re-runs against the current stored listing on every request; results automatically reflect the latest sync data.
Keyword Comparison
Section titled “Keyword Comparison”GET /api/v1/apps/{platform}/{externalId}/keywords/compare?app_ids=1,2,3&locale=en-USCompares keyword usage across several apps — useful for competitive keyword analysis.
The Keywords tab on the app detail page shows:
- A keyword list sorted by density
- N-gram size filter (1, 2, 3)
- Language picker
- Comparison view with competitor apps
Technical Details
Section titled “Technical Details”- Service:
KeywordAnalyzer(analyzeListing()/analyzeText()return arrays — they do not write to the DB) - Source: The current
StoreListingrecord for the requested(app_id, locale) - Controllers:
KeywordController@indexandKeywordController@comparerecompute on every request - Minimum word length: 2 characters