Why Screenshot A/B Testing Often Fails in ASO and When It Works
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Based on insights from multiple ASO practitioners and mobile app founders, this comprehensive analysis explores why screenshot A/B tests frequently fail to improve conversion rates and identifies the conditions where they actually work.
Original discussion: View Tweet
I glanced through App Mafia's course and watched the ASO video by @zach_yadegari on Cal AI. He mentioned there that even though they tested different creatives, they couldn't improve the conversion rate of the initial version.
This aligns with another founder I've spoken to recently (their app has 200k-300k+ of mostly organic downloads). That sparked my interest, so I started a discussion on our Slack group, which led to some fascinating insights.
In the world of App Store Optimization (ASO), screenshots are often considered one of the biggest levers for improving conversion rates. Yet, many founders and growth marketers report the same frustrating experience: no matter how many new designs they test, the original screenshots keep winning.
Key Finding
Based on insights from practitioners working on apps ranging from a few thousand downloads to hundreds of thousands per month, screenshot A/B tests fail to deliver improvements about 90% of the time.
1. Large Apps Behave Differently from Small Apps
For smaller apps, especially those with less than 10k downloads per month, screenshots can swing conversion rates noticeably. Users are less familiar with the brand, and visuals can make or break trust.
By contrast, established apps with big traffic (100k+ downloads/month, or heavy brand search traffic) are harder to influence. Users already know the app from ads, TikTok, or social media, and are coming with intent. The original screenshots feel "familiar," and new creative variations often perform worse.
As one ASO consultant put it: "It's harder to move the needle the bigger an app is, or to be more specific, the more redownloads or branded search downloads an app has."
2. PPO Tests Are Noisy, and the First Days Mislead
Multiple practitioners noted that Apple's PPO (Product Page Optimization) results often look unstable or misleading in the first 2–3 days. That's because Apple uses an adaptive optimization algorithm that needs time to calibrate. Early "winners" or "losers" are often overturned after several weeks.
One expert stressed the need to run A/A/B tests first (testing the same screenshots against themselves) to check if the testing environment is reliable before making conclusions.
"The first two days of PPO are always completely off. Consistency over time is key."
3. Iteration Usually Works Better Than Revolution
Drastic redesigns almost always underperform. Instead, small tweaks to existing winning screenshots — bigger text, clearer copy, subtle color shifts, adding social proof — tend to bring more reliable improvements.
One founder shared that even a single copy change on the first screenshot led to a few percentage points improvement in conversion.
This echoes what many marketers observe: "beautiful" or creative redesigns may look great subjectively, but data often shows they confuse users or break familiarity.
4. Traffic Source Matters More Than You Think
If most downloads come from brand searches or paid UA on TikTok/Instagram, screenshots don't matter much. Those users already decided to install before reaching the store.
But on generic keyword traffic ("calorie tracker," "meditation app") or organic browse placements, screenshots can have a bigger impact.
This explains why one popular calorie-tracking app sees little movement in PPO tests — 70–80% of its installs are from brand search or social ads.
5. Successful Tests Can Create Compounding Growth
While most PPOs "don't work" (90% of the time, according to one expert), when you do find a clear winner, the effects cascade:
- •Conversion rate increases
- •Installs increase
- •Keyword ranking improves
- •Which further boosts conversion
That's why top apps keep testing constantly, even if most tests fail. The rare wins more than pay for the effort.
6. Don't Ignore Blended Effects with Ads
One interesting observation: running Apple Search Ads (ASA) with custom product pages can sometimes show indirect uplift. Even if click-through rates drop, total installs (ad + organic combined) may rise — because users see the new creatives and convert organically instead. This kind of blended effect is often overlooked, but can be a real growth lever.
7. Practical Recommendations
- •Run tests long enough: 3–7 weeks is common before calling a winner.
- •Start small: Tweak one image, copy size, or background color rather than redesigning everything.
- •Segment traffic: Evaluate branded vs generic vs browse traffic separately.
- •Expect early noise: Ignore the first 2–3 days of PPO data.
- •Validate with A/A/B tests: Check Apple's algorithmic reliability.
- •Think compounding: Keep testing even if most changes fail, because one breakthrough test can compound into lasting growth.
Final Thoughts
For most apps, screenshot testing is not dead — it's just misunderstood. Big brands face diminishing returns due to traffic mix and user familiarity, while smaller apps can see wild swings in conversion from visual changes.
The key is patience, iteration, and data discipline. Beautiful doesn't mean better. And sometimes, the best growth hack is simply making your winning screenshot copy a little bigger.
This article is based on insights shared by @filippkowalski and collaborative discussions within the mobile development community. Original discussion: View Tweet