How to Generate App Icons for iOS and Android

You’ve finally settled on a logo for your app, and now Xcode or Android Studio is asking for it in a dozen different pixel sizes — 20x20, 40x40, 60x60, 76x76, 120x120, 512x512, and more, each one named exactly right or the build tooling rejects it. Resizing one image into a dozen exact dimensions by hand in an image editor is the kind of task that eats twenty minutes and produces at least one mistake.

The frustrating part isn’t the concept — it’s scaling one square image down (or up) to a fixed list of required sizes without introducing blur, wrong aspect ratios, or a filename that doesn’t match what the platform expects.

What generating app icons actually involves

Both iOS and Android require the same source artwork rendered at multiple fixed pixel dimensions, because different parts of the OS (home screen, settings, notifications, app store listing) each expect their own size. Get one size wrong or blurry and it’s the kind of thing that looks fine in development and embarrassing once the app ships.

The actual task is simple in principle: start from one high-resolution square image, and produce a full, correctly named set of resized PNGs without quality loss at any size.

Why people get stuck here

• Different size lists for each platform. iOS and Android don’t share the same required dimensions, so a size chart that works for one platform doesn’t cover the other.
• Manual resizing degrades quality. Repeatedly resizing the same file in a general image editor, rather than resizing once from the original at each target size, introduces visible blur at smaller sizes.
• Non-square source art. Icons need to start from a perfectly square image — a slightly rectangular logo produces stretched or cropped icons downstream.
• Losing track of which size is which. Without clear labels, it’s easy to upload the wrong size into the wrong slot in Xcode or Android Studio’s asset catalog.

What a good app icon generator looks like

Covers both platforms’ full size lists

You shouldn’t have to look up iOS and Android’s exact required dimensions separately — the tool should already know them and generate every size in one pass.

Renders each size from the original

Every output size should be generated fresh from your original source image, not resized from an already-resized version, to avoid compounding quality loss.

Lets you preview before downloading

Seeing each generated size rendered at actual scale catches problems — like a logo that reads fine at 512px but turns into a blurry blob at 20px — before you ship it.

Common mistakes to avoid

• Starting from a non-square or low-resolution source image, which limits how clean the smallest generated icons can look.
• Resizing the icon set once and reusing it across multiple app versions without regenerating from the original when the logo changes.
• Mixing up iOS and Android size requirements and uploading the wrong set to the wrong platform’s asset catalog.
• Forgetting that some platforms round icon corners automatically — designing a square icon with important detail right at the corners can get clipped.
• Skipping the largest sizes (like the 1024x1024 App Store icon) because they’re not needed for the running app, then scrambling for it at submission time.

How to do it with App Icon Generator

Online Tool Store’s App Icon Generator runs entirely in your browser — your source image is never uploaded to a server.

1. Open the App Icon Generator tool.
2. Upload a square source image, ideally at least 1024x1024 pixels.
3. Preview the generated icon set across all required iOS and Android sizes.
4. Download each size individually as a PNG, ready to drop into your project’s asset catalog.

Because everything happens locally, it’s a fast way to regenerate a full icon set any time your logo changes, without re-uploading anything.

Frequently asked questions

What’s the minimum source image size I should start with?

Start with at least 1024x1024 pixels, since that’s typically the largest size either platform requires (for App Store or Play Store listings), and every smaller size can be generated cleanly by downscaling from there.

Do iOS and Android need different icon shapes?

The underlying image should be a plain square in both cases — the platforms apply their own corner rounding or masking automatically, so you don’t need to pre-round the corners yourself.

Can I use a transparent background for my app icon?

It depends on the platform’s requirements — some app stores reject icons with transparency in the outer edges. Check your target platform’s current guidelines, since a solid background is generally the safer default.

Final thought

An app icon set is one of those small technical requirements that’s easy to underestimate until you’re staring at a rejected build. Generate every size correctly once, from a clean square source, and you won’t have to think about it again until the logo changes.

Try the free App Icon Generator tool