Question 1

What icon size should I upload?

Accepted Answer

Upload a square 1024×1024 pixel image, ideally as a PNG without transparency. This is the canonical App Store size and gives the resizer enough resolution to downsample cleanly to every smaller size without artifacts. If your source is larger (2048×2048 or bigger) that also works, but there is no visual benefit past 1024 for icon output. Non-square images are automatically center-cropped, and images smaller than 512×512 will be upscaled with a warning, which usually looks poor and is not recommended. If you only have a vector source like SVG or Figma, export at 1024×1024 PNG first and then upload that.

Question 2

Which icon sizes does this tool generate?

Accepted Answer

For iOS, a single 1024×1024 PNG plus a modern single-size AppIcon.appiconset Contents.json — Xcode 14 and later auto-compile every runtime size at build, so the legacy 15-slot fanout is no longer needed. For Android, 48, 72, 96, 144 and 192 pixel launcher icons for the mdpi, hdpi, xhdpi, xxhdpi and xxxhdpi mipmap densities plus a 512×512 Google Play Store listing icon. For Web and PWA, a 180 Apple touch icon plus 192 and 512 android-chrome icons plus a valid web manifest — legacy 16, 32 and 48 favicons are intentionally omitted because modern browsers no longer request them. For Expo, icon.png, adaptive-icon.png and favicon.png at their standard sizes.

Question 3

Does my icon get uploaded to a server?

Accepted Answer

No. Every operation in this tool runs entirely inside your browser using the Canvas API and JSZip. Your icon file never leaves your device, no data is sent to RapidNative, and no server sees the image. This means the tool works offline once loaded, respects intellectual property for unreleased apps, and is safe for icons under NDA. The ZIP file containing all sizes is assembled locally and downloaded directly from your browser. There is nothing to log, nothing to track, and nothing that could leak if the network is unreliable.

Question 4

Does the ZIP include a valid Xcode Contents.json?

Accepted Answer

Yes. When iOS is selected, the ZIP contains an AppIcon.appiconset folder with a modern single-size Contents.json that references the 1024×1024 icon under the universal iOS idiom. Drag the folder into Assets.xcassets in Xcode 14 or later, and Xcode auto-compiles every runtime size (Home Screen, Spotlight, Settings, Notifications across iPhone and iPad) from that single source at build time. There is no manual slot dragging, no legacy 15-slot fanout to manage, and no risk of missing an icon slot. Requires Xcode 14 or later — for older Xcode versions you would still need the legacy per-slot fanout, which this tool no longer emits.

Question 5

How is the resizing quality?

Accepted Answer

The tool uses a multi-step downsampling strategy, halving the source progressively until close to the target size and then applying the final scale. This produces significantly better output than a single-pass resize because bilinear scaling introduces blur when the scale factor is very small. The browser Canvas API imageSmoothingQuality is set to high on every step. For most icons the result is visually indistinguishable from tools like Pica or ImageMagick. If your icon has very fine detail like 1-pixel gridlines, upload a PNG rather than JPEG so no compression artifacts are baked into the source.

Question 6

What is an Android adaptive icon and does this tool support it?

Accepted Answer

Android adaptive icons are a two-layer format introduced in Android 8.0 where the launcher composes a foreground layer and a background layer at runtime, letting device manufacturers apply their own mask shape like circle, squircle or squircle rounded. The foreground layer needs a specific safe zone with padding around the visible content. This tool generates the traditional legacy launcher icons for each mipmap density and the Google Play Store icon, which cover the majority of real-world use cases. For a full adaptive icon set with separate foreground and background PNGs you will need a dedicated adaptive icon tool because the foreground layer usually needs to be redesigned with extra padding rather than mechanically resized from a full-bleed icon.

App Icon Resizer

iOS — modern single-size app icon

Android launcher icons + Play Store

Web / PWA and Expo output

Frequently Asked Questions

iOS — modern single-size app icon

Android launcher icons + Play Store

Web / PWA and Expo output

Frequently Asked Questions