UK Marketing ASO Guide: How to Increase Conversion Through A/B Testing Your App

Did you know users spend just 7 seconds on average on an app store page?

With skyrocketing acquisition costs eating into marketing budgets, this fleeting decision window determines whether your ad spend lives or dies—every user who clicks an ad but doesn't download spikes your cost per install by the minute.

That's why A/B testing is a growth team's secret weapon. By comparing different app store assets (from hero images to feature descriptions), you can pinpoint exactly what drives users to hit "download" and climb the charts with the same budget.

This guide will help you comprehensively understand A/B testing to increase app conversion.

What is A/B Testing?

"A/B Test, also known as split testing, is a randomized experimentation process where two or more variants (A and B) of a single variable are shown to different segments of users at the same time to determine which version performs better.

In the context of mobile apps and digital marketing, A/B testing is a critical tool to optimize user experience, improve conversion rates, and ultimately drive more downloads and revenue."

Learn More 👉 [ASO Glossary] A/B Testing

What app assets do you need to test?

App Icons

Eye-tracking tests show that high-saturation colors pack more visual punch on small mobile screens.

Take Instagram, for example: when it swapped its icon from a retro brown camera to a vibrant gradient of purple, pink, and orange, download conversions reportedly jumped by over 20%.

This case underscores a key insight— the visual impression formed in just 0.8 seconds dictates a user's next move, which, in app marketing, means hitting download.

App Screenshots

Screenshots on the Apple App Store and Google Play Store give you a great test room. You can use them for testing search results or app store listings. Here are some examples of what you can test on a screenshot.

1. Background color - light vs. dark

Let's start with back ground color.

This is a very easy test to run. Test light backgrounds against dark backgrounds to determine which enhances readability and visual appeal.

Light backgrounds often feel clean and modern, while dark ones can create a premium or immersive vibe, depending on your app's aesthetic.

2. Background - solid vs patterned

Another simple test you can try for the background is to use a pattern or a solid color.

Compare solid color backgrounds with patterned or textured ones (e.g., gradients, subtle grids, or abstract designs).

Solid colors can keep the focus on the app interface, while patterns may add personality but risk distraction.

Test to see which aligns better with your brand and user preferences.

3. Text color

The last test that involves color is the color of the captions.

Experiment with text colors that contrast with the background for readability (e.g., black text on a white background vs. white text on a dark background).

Test vibrant colors for emphasis or neutral tones for a minimalist look to gauge user response and engagement.

4. Text Styles -  Size

There are so many things we can try when it comes to text!

The size of the font can be also important, so test different text sizes to balance visibility and aesthetics.

Larger text can emphasize key messages but may crowd the screenshot, while smaller text keeps the design clean but risks being overlooked.

There's one thing you should notice: ensure legibility across screen sizes for the best results.

5. Text Styles -  Font

How you present your headlines can determine whether views translate into downloads, which depends on your audience. This makes it a valuable test item.

Rounder, thicker fonts tend to feel friendlier, while thinner, narrower fonts convey authority.

Use sans-serif fonts (e.g., Helvetica) for a modern feel, serif fonts (e.g., Times New Roman) for a classic look, or bold display fonts for emphasis.

Test different font styles to ensure they reflect your app's tone and remain legible across devices to maximize impact.

6. Text placement - top vs. bottom

Where you place your text is also important.

Experiment with placing text overlays at the top versus the bottom of the screenshot.

Top placement may grab attention first, while bottom placement can complement the app interface without obstructing key visuals.

Test to find the optimal balance for user focus.

7. Text Length

When it comes to captions, less is more, but one size doesn't fit all situations.

If your current captions are long, try shortening them, and if they're already short, try giving them more definition.

You can also try to vary the length of your call-to-action (CTA) text, such as short phrases like "Get Started" vs. longer ones like "Unlock Your Free Trial Today."

Test concise CTAs for urgency against descriptive ones for clarity to see which drives more clicks.

By A/B testing these elements and analyzing app store analytics, you can optimize your screenshots to improve click-through rates and conversions.

Tailor each test to your app's target audience and core value proposition to ensure the screenshots effectively communicate your app's unique appeal.

App Preview Videos

Including a video on your app store page can significantly increase conversion rates, though outcomes differ by product.

To measure its effectiveness, incorporate "video vs. no video" as a key variable in A/B testing to determine its impact on your audience.

When creating videos, avoid duplicating content from screenshots. Focus on your unique selling proposition (USP), as viewers typically lose interest after 20 seconds.

You can A/B test by changing the following:

• Features: Which feature should the video showcase?

• Color: Test different color schemes.

• Duration: Vary the video length.

• Number of videos: Test multiple videos (available only on the Apple App Store).

You can then compare app download rates after users view the video.

Note: videos auto-play in the Apple App Store, so this metric may not be entirely reliable.

What More You Can Test About?

Beyond app icons, screenshots, and preview videos, A/B testing can extend to other critical app store assets and elements to further optimize conversions.

Here are additional areas to explore, each with specific test ideas to refine your app store presence and drive downloads:

App Description

The app store description is a key touchpoint for conveying your app's value and persuading users to download.

A/B testing different aspects of the description can uncover what resonates most with your audience.

👉 How to Maximize the Effectiveness of App Description?



1. Tone and Voice

Test a friendly, conversational tone against a professional, feature-focused tone.

Measure which tone drives higher engagement based on your target audience's preferences.

2. Length of Description

Experiment with a concise description (e.g., 100-150 words) versus a detailed one (e.g., 300-400 words).

Short descriptions may appeal to users seeking quick info, while longer ones can provide in-depth context for complex apps.

Test to see which length maximizes conversions.

3. Keyword Emphasis

Test descriptions with heavy keyword optimization for app store search algorithms versus user-focused, benefit-driven copy.

Monitor impacts on both search visibility and download rates.

4. Call-to-Action Placement

Test placing a strong CTA at the beginning, middle, or end of the description.

Early CTAs may capture impulsive users, while end-placed CTAs can seal the deal after detailing benefits.

App Title & Subtitle

The app title and subtitle are critical for both visibility and conversion. They need to be clear, memorable, and optimized for search.

1. Title Length

Test a short, catchy title versus a descriptive one.

(For example:  "FitTrack" vs."FitTrack: Workout & Nutrition")

Short titles are memorable but may lack context, while longer titles can improve search relevance.

Check which drives more impressions and downloads.

2. Keyword Inclusion in Title/Subtitle

Experiment with including high-traffic keywords in the title or subtitle.

Track how keyword-heavy titles impact search rankings versus brand-focused ones that prioritize recognition.

3. Emotional vs. Functional Appeal

Test emotionally engaging subtitles against functional ones.

(For example:  "Unleash Your Creativity" vs. "Edit Photos in Seconds")

Measure which approach better aligns with your audience's motivations.

Seasonal or Event-Based Themes

Timely events or seasons elements can effectively attract your users.

Test seasonal visuals and texts and track whether time-sensitive promotions drive urgency and boost downloads.

Example 👉 Seasonal ASO Strategies for Christmas

Technical Elements

Technical aspects of your app store listing can also be tested to optimize performance.

1. App Category

Test placing your app in different categories (e.g., "Productivity" vs. "Business" for a task management app).

Monitor how category selection affects discoverability and conversion rates.

2. File Size

For apps with larger file sizes, test mentioning "Optimized for Fast Download" versus not addressing size at all.

This can reassure users concerned about storage or data usage.

3. Update Frequency

Test how frequently you push app store updates with new screenshots or descriptions.

Frequent updates may signal an active app but risk overwhelming users with changes.