How Popularity & Difficulty scores work

Popularity (0–100)

Popularity estimates how much a keyword is searched in the store. A higher score means more people are typing that term, so ranking for it can drive more installs. It's derived from store search-demand signals — primarily App Store and Google Play autocomplete behavior — and normalized onto a consistent 0–100 scale so you can compare any two keywords at a glance.

Think of Popularity as a directional traffic signal, not a precise monthly search count. A keyword at 70 clearly has more demand than one at 30; the exact gap between 68 and 71 matters far less than the broad tier.

Difficulty (0–100)

Difficulty estimates how hard it is to reach the top of the results for a keyword. A higher score means the apps already ranking are strong and well-established, so displacing them takes more work. We calculate it by analyzing the apps that currently rank for the term and weighing how formidable they are as a group.

What feeds the score

Without giving away the recipe, the factors that push Difficulty up include:

• Title relevance of the top apps — keywords sitting in app titles signal strong, direct competition.
• Strength of the incumbents — install volumes, review counts, and ratings of the apps already ranking.
• Market saturation — how many established apps are competing for the same term.
• Brand pull — branded terms are dominated by their owner and are hard to break into.

As a rough guide: 0–30 is low competition (a real opportunity), 30–60 is moderate, and 60–100 is highly competitive.

Gap = Popularity − Difficulty

The Gap column is simply Popularity minus Difficulty. A large positive Gap is the sweet spot — high demand with low competition. These are the keywords worth prioritizing first.

Why three ASO tools show three different numbers

If you compare Sonar, AppTweak, and Appfigures side by side, the Popularity and Difficulty values won't match — and that's expected. Every ASO tool builds these scores from its own data sources and its own proprietary model, then normalizes them onto its own scale. There is no single industry-standard number.

So the right way to use any of them is to rank keywords against each other within one tool — not to compare absolute numbers across tools. Inside Sonar, a keyword at 70 popularity really is more searched than one at 40; that relative ordering is what you act on.

How to use them together

Hunt for keywords with high Popularity and low Difficulty (a positive Gap) — enough people are searching to matter, and the competition is beatable. Sort by Gap, filter out anything above your Difficulty comfort level, and start with the terms where you can realistically crack the top results.