The Problem With App Store Search Data
Apple doesn't give you raw search counts. Google doesn't either, at least not for the Play Store. Unlike web SEO where tools like Google Keyword Planner show you "10K-100K monthly searches," app store keyword research is built on relative scores and educated guesses.
For the iOS App Store, the primary metric is Apple's Search Popularity (SP) score — a number from 5 to 100 that represents relative search volume. But what does an SP of 45 actually mean in terms of real searches? How many people are actually typing that keyword into the App Store every day?
This is the question that matters for making practical ASO decisions, and it's answerable.
The SplitMetrics Formula
The most rigorous public research on this comes from SplitMetrics, who analyzed data from Apple Search Ads campaigns across thousands of keywords. They found that the relationship between SP and actual search impressions follows an exponential curve:
Max Daily Impressions = 254.4443 exp(0.0615 SP)
This formula estimates the maximum daily impressions a keyword generates — meaning the total number of times apps could appear in search results for that keyword per day. Your actual impressions will be a fraction of this based on your ranking position.
The exponential nature is critical: each 10-point increase in SP roughly doubles the search volume. An SP 60 keyword doesn't get 50% more searches than an SP 40 keyword — it gets roughly 3.5x more.
The Complete Reference Table
Here's the full breakdown across the SP spectrum, with estimated daily impressions, monthly volume (daily x 30), and practical volume labels:
| SP Score | Daily Impressions | Monthly Volume | Label |
|---|---|---|---|
| 16 | ~400 | ~12,000 | Very Low |
| 18 | ~450 | ~13,500 | Very Low |
| 20 | ~870 | ~26,000 | Very Low |
| 22 | ~1,000 | ~30,000 | Low |
| 25 | ~1,200 | ~36,000 | Low |
| 28 | ~1,400 | ~42,000 | Low |
| 30 | ~1,600 | ~48,000 | Low |
| 32 | ~1,900 | ~57,000 | Low-Medium |
| 35 | ~2,300 | ~69,000 | Medium |
| 38 | ~2,700 | ~81,000 | Medium |
| 40 | ~2,800 | ~84,000 | Medium |
| 42 | ~3,400 | ~102,000 | Medium |
| 45 | ~4,100 | ~123,000 | Medium |
| 48 | ~4,800 | ~144,000 | Medium-High |
| 50 | ~5,600 | ~168,000 | Medium-High |
| 55 | ~7,600 | ~228,000 | High |
| 60 | ~10,000 | ~300,000 | High |
| 65 | ~13,600 | ~408,000 | High |
| 70 | ~18,000 | ~540,000 | Very High |
| 75 | ~25,000 | ~750,000 | Very High |
| 80 | ~33,000 | ~990,000 | Very High |
| 85 | ~60,000 | ~1,800,000 | Ultra High |
| 90 | ~80,000 | ~2,400,000 | Ultra High |
| 95 | ~110,000 | ~3,300,000 | Ultra High |
| 100 | ~200,000+ | ~6,000,000+ | Ultra High |
These numbers are for the US App Store. Other markets are proportionally smaller — the UK is roughly 25-30% of US volume, Germany about 15-20%, and so on.
What the Volume Labels Mean in Practice
Very Low (SP 16-20, <1,000/day): These keywords exist but barely register. Even ranking #1 would only bring a handful of downloads daily. Worth including in metadata if highly relevant, but don't optimize specifically for them.
Low (SP 21-34, ~1,000-2,000/day): The long tail. Individually they won't move the needle, but collectively a dozen low-volume keywords in your metadata can compound into meaningful traffic. Many of these are now invisible in Apple's API since the October 2025 cutoff at SP 35.
Medium (SP 35-49, ~2,300-5,000/day): The goldmine for indie apps. These keywords have enough volume to drive real downloads (ranking in the top 3 for an SP 45 keyword could mean 50-200 downloads/day) but typically aren't dominated by massive incumbents. This is where smart ASO pays off the most.
High (SP 50-69, ~5,600-16,000/day): Competitive territory. You'll need strong ratings, good download velocity, and likely a well-optimized title to rank here. Achievable for established indie apps with 4.5+ ratings and thousands of reviews.
Very High (SP 70-85, ~18,000-60,000/day): Dominated by top apps. Think "photo editor," "weather app," "music player." Only realistic if your app is already a category leader or you're targeting a very specific variant.
Ultra High (SP 86-100, ~70,000-200,000+/day): Brand keywords and category-defining terms. "Instagram," "TikTok," "Spotify." Not viable targets for ASO unless it's your own brand name.
The Sweet Spot: SP 35-55, Difficulty Under 40
After analyzing thousands of keyword-app combinations, a clear pattern emerges for indie app success:
Target keywords where SP is between 35 and 55 and keyword difficulty is below 40. These keywords have enough volume to meaningfully impact downloads (2,300-7,600 daily impressions) while being achievable for apps without massive install bases.
A keyword with SP 45 and difficulty 30 is worth far more to an indie developer than a keyword with SP 75 and difficulty 80. You'll never rank for the latter, but you can realistically reach the top 5 for the former with good metadata optimization and decent ratings.
When SP Data Isn't Available
Since Apple's October 2025 change, keywords with SP below 35 no longer return popularity data through the Search Ads API. For these terms, you need alternative signals.
Autocomplete priority is the best free proxy. When you search in the App Store, Apple returns suggestions with priority scores from 0 to 10,000. Higher priority correlates with higher search volume:
| Autocomplete Priority | Approximate SP Equivalent |
|---|---|
| 0-2,000 | SP < 20 |
| 2,000-4,000 | SP 20-30 |
| 4,000-6,000 | SP 30-40 |
| 6,000-8,000 | SP 40-55 |
| 8,000-10,000 | SP 55+ |
This isn't a precise mapping — autocomplete priority is influenced by factors beyond pure search volume, including trending behavior and editorial curation. But for keywords below the SP 35 cutoff, it's the most accessible signal available.
Using This Data for Keyword Selection
Here's a practical framework for choosing keywords:
- Start with relevance. No amount of volume matters if the keyword doesn't match what your app does. Users who search "meditation timer" and find a workout app will not download it.
- Check volume viability. Use the SP-to-impressions table above. If the keyword is below SP 30 (~1,600 daily impressions), it needs to be extremely relevant or part of a larger long-tail strategy.
- Assess competition. Look at the top 10 apps ranking for the keyword. If they all have 100,000+ reviews and 4.7+ ratings, you're unlikely to break in regardless of volume.
- Calculate opportunity. The ideal keyword has medium volume (SP 35-55), low-to-medium difficulty (<40), and high relevance to your app. These are the keywords worth putting in your title and subtitle.
- Fill remaining metadata slots with long-tail variants. Once your title and subtitle target your primary keywords, use the keyword field for lower-volume variants and related terms.
The goal isn't to find one perfect keyword. It's to build a metadata strategy where your title targets 2-3 medium-volume opportunities, your subtitle reinforces those while adding 2-3 more, and your keyword field covers 15-20 long-tail variations. That's how you maximize organic search coverage on the App Store.