How we check our data

iOS rankings: validated against DataForSEO

Sonar's iOS keyword rankings come from Apple's iTunes Search API. To verify that its result order reflects real App Store rankings, we compared it against DataForSEO's true App Store ranking data across 14 broad, brand, and long-tail queries. The results:

• Rank order matched within ±2 positions through the top 20 on every query.
• Exact #1 agreement on every query — the app DataForSEO reported at #1 was the app we reported at #1, every time.

That makes it a faithful rank-tracking source, not just a discovery feed: the position you see in Sonar is the position users see in the store, give or take a couple of spots deep in the results.

iOS popularity: Apple's own number, not an estimate

For iOS keywords, Sonar's Popularity score is Apple's Search Popularity — the 5–100 demand score Apple itself publishes in its Search Ads console. There is no model in the loop: it's the Apple-reported value. Tools that don't source this number directly are estimating it.

Apple floors many niche terms at 5, so a large band of long-tail keywords all read "5" regardless of their real demand. For those censored keywords Sonar computes a proprietary proxy estimate to disambiguate them. The API tells you exactly which value you're looking at: popularity_source is apple or proxy, and popularity_proxy carries the estimate alongside the Apple value. No silent blending.

Android popularity: calibrated against real Apple data

Google publishes no search-demand score for Play Store keywords, so Android Popularity has to be an estimate. We calibrate ours against the best available ground truth: real Apple Search Popularity for the same 57 keywords across both stores. Against that set, the estimator achieves a mean absolute error of 12.5 points and a Spearman rank correlation of 0.775 — the relative ordering you sort by holds up well.

The primary signals are a Google Play autocomplete depth probe (how few characters a user must type before the term surfaces in suggestions — a direct read on store search behavior) and the install volumes of the top-10 ranking apps.

What the scores mean

For how to read Popularity, Difficulty, and Gap — and why different ASO tools show different numbers for the same keyword — see How Popularity & Difficulty scores work.