App Icon Batch Generation: Create All iOS & macOS Sizes in Seconds

When developing iOS/macOS apps, App Icon creation is an unavoidable task.

But App Icons aren't just one size. App Store submission requires 20+ different sizes for various devices and contexts.

• iPhone, iPad, Apple Watch...
• @1x, @2x, @3x...
• 1024×1024 for App Store...

Manually resizing each one takes 30+ minutes.

This article shows you how to batch generate all sizes from a single 1024×1024 source image in seconds.

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Required App Icon Sizes

iOS Apps (2025)

macOS Apps

Total: 20+ sizes required

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Traditional Methods and Their Problems

Method 1: Manual Creation in Photoshop

1. Open 1024×1024 source image
2. "Image" → "Image Size" to resize
3. "Save As"
4. Repeat 20+ times...

⏰ Time required: 30 minutes to 1 hour

Risk of size mistakes or naming errors.

Method 2: Online Generators

Web-based App Icon generation services exist, but:

• ❌ Requires uploading images to servers
• ❌ Uncomfortable uploading unreleased app icons
• ❌ Doesn't work offline

Method 3: Command-Line Tools

Automation via sips or shell scripts is possible, but:

• ❌ Requires command-line knowledge
• ❌ Script creation and maintenance is tedious
• ❌ Needs updates when new sizes are added

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Most Efficient Method: DockBuddy Resizer

DockBuddy Resizer batch generates all sizes from a 1024×1024 source in seconds.

Steps

1. Prepare a 1024×1024 source image

   • PNG format recommended (supports transparency)
   • Must be square

2. Launch DockBuddy Resizer

3. Drag & drop your source image

4. Select App Icon preset

   • "iOS App Icon"
   • "macOS App Icon"
   • Or both

5. All sizes output in seconds

That's it—20+ sizes generated automatically.

Batch Processing Power

Developing multiple apps? Drop multiple source images at once to batch generate App Icons for all apps.

Example: 5 apps × 20 sizes = 100 files

Traditional method: 2+ hours DockBuddy Resizer: ~30 seconds

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Importing to Xcode

Steps to add generated App Icons to your Xcode project:

Method 1: Drag Directly to Assets.xcassets

1. Open project in Xcode
2. Select Assets.xcassets
3. Select AppIcon (or right-click → "New App Icon" if missing)
4. Drag generated images to corresponding slots

Method 2: Bulk Import from Finder

1. Open the AppIcon.appiconset folder in Finder via Assets.xcassets
2. Copy all generated image files
3. Restart Xcode

Contents.json Update

After adding images, verify Contents.json is correctly updated. DockBuddy Resizer outputs filenames that Xcode recognizes easily.

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App Icon Best Practices

1. Create Source at Maximum Size

Always create your source at 1024×1024 or larger. Upscaling smaller images degrades quality.

2. Use PNG for Transparency

For macOS rounded icons or any transparency needs, save as PNG format.

3. Check Visibility at Small Sizes

What looks great at 1024×1024 may become unclear at 16×16 or 29×29. Preview small sizes after generation.

4. Review App Store Guidelines

Check Apple's Human Interface Guidelines for recommended design practices.

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FAQ

Q: Does it work with transparent PNGs?

A: Yes, transparency is preserved across all sizes. Choose PNG as output format.

Q: Does it support new sizes added in iOS 18?

A: DockBuddy Resizer is regularly updated to support the latest iOS/macOS required sizes.

Q: Can it generate Apple Watch icons?

A: Yes, watchOS sizes are included.

Q: Can I generate icons for multiple apps at once?

A: Yes, drop multiple source images simultaneously to batch generate App Icons for all apps.

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Integrating into Your Development Workflow

Example workflow for smooth App Icon generation:

Design creation (Figma/Sketch)
    ↓
Export at 1024×1024
    ↓
Batch generate with DockBuddy Resizer
    ↓
Import to Xcode
    ↓
Build & Test

CI Integration

For large teams, consider integrating App Icon generation into CI/CD pipelines. DockBuddy Resizer is a desktop app, but it's perfect for optimizing local development environments.

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Summary

App Icon creation is a surprisingly time-consuming part of app development.

Drag & drop a 1024×1024 source to batch generate all iOS/macOS sizes.

Developers, free yourselves from App Icon creation hassle.

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Related Articles

• Mac Image Resizer Comparison
• How to Resize Images on Mac - Complete Guide

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Try DockBuddy Resizer

Download Free

$9.99 one-time to streamline App Icon creation.