App Asset Studio

What is App Asset Studio?

App Asset Studio is a free, browser-based tool that prepares the images you need to publish a mobile app: App Store and Google Play screenshots in the exact required resolutions, App Store product page headers and search-result images, and Google Play app icons, feature graphics, and TV banners. Upload a screenshot or design (drag and drop, select, or paste with Ctrl/⌘+V), pick a target device or asset type, and export a correctly sized image. If the aspect ratio differs, the image is scaled up to fill the frame with no empty margins and the overflow is cropped from the center. No design software and no manual pixel math required.

The studio was built by an independent app developer who got tired of resizing the same screenshots for every device size at every release. The whole workflow lives on one page: upload and configure on the left, check the live preview in the middle, then collect finished assets in the library and download them together as a ZIP.

How it works — your images never leave your device

Everything runs locally in your browser. Resizing and composition use the Canvas API, and background removal runs on a machine-learning model compiled to WebAssembly that is downloaded to and executed on your device. Original and processed images are never uploaded to any server — which also makes the tool safe to use on unreleased app designs and confidential material.

Because processing is local, speed depends on your device rather than on a server queue. The first background removal takes a moment while the model downloads; after that the browser caches it and later runs are much faster.

Store screenshot sizes, explained

Apple and Google both require screenshots in specific pixel sizes before you can submit an app. App Store Connect only accepts the resolutions defined for each display size. For iPhone, a screenshot for the Dynamic Island medium display (iPhone 16, 17 and similar; 1206 × 2622 or 1179 × 2556) is required, and it also accepts sets for the large display (Pro Max and Plus models; 1320 × 2868, 1290 × 2796 or 1260 × 2736) and for older Face ID models. iPad apps need 13-inch iPad screenshots (2064 × 2752 or 2048 × 2732). Google Play is more flexible: each side must be 320–3840 px and the longer side no more than twice the shorter, with 1080 × 1920 or higher recommended for phone screenshots.

The studio sets the exact resolution when you pick a device, so exported files pass store validation as they are. Choose the model for each device your app targets and reuse the same source image. If the source and target aspect ratios differ, the image is cropped from the center with no white bars, so check that nothing important sits near the edges. The header, search-result, and Google Play graphic modes build spec-sized files from a single image, and you can create the header and search result together or choose the universal 16:9 size. Alpha channels (transparency data), which the stores do not accept, are removed from both screenshots and graphics, and transparent areas are filled with white. The Google Play app icon is the exception and keeps its transparency.

Getting better results

• Start from the highest-resolution source you have — upscaling a small screenshot always loses sharpness.
• Match orientation and aspect ratio: a capture taken on the target device fits the required size with no cropping. A source with a different ratio loses its overflow from the center.
• Background removal works best when the subject clearly contrasts with the background; busy backgrounds may need a retouch afterwards.
• Keep important text away from the edges — a source with a different ratio gets its edges cropped, and store listings crop and frame screenshots differently across devices.
• Paste an image straight from the clipboard with Ctrl/⌘+V. You can attach up to 10 images at once; the header, search-result, and graphic modes use a single image.

Frequently asked questions

Is App Asset Studio really free?

Yes. All features — resizing, background removal, batch ZIP export — are free and require no account. The service is supported by ads.

Are my images uploaded to a server?

No. Processing runs entirely in your browser using the Canvas API and WebAssembly. You can verify this yourself: the network tab of your browser's developer tools shows no image uploads.

Which file formats can I upload?

PNG, JPEG, and WebP images are supported. Store screenshots and graphics export as JPG (the universal header/search image and the Play app icon are PNG); background removal exports as transparent PNG. Store outputs have their alpha channel removed, as the store specs require (except the Play app icon).

Can I use the exported images commercially?

Yes. The rights to your uploaded images and the results you create from them belong entirely to you. See the Terms of Service for details.

Why is the first background removal slow?

On first use the ML model (a few megabytes) is downloaded and compiled in your browser. Later runs reuse the cached model and finish much faster.

How is the alpha channel (transparency) handled in the output?

The alpha channel stores transparency for each pixel. App Store and Google Play do not accept screenshots or graphics that contain an alpha channel, and a file can be rejected even if nothing in it looks transparent. For that reason, store image editing results are exported without an alpha channel. Transparent or semi-transparent areas are composited onto white and become white, while fully opaque images lose only the channel, with no visible change. The exception is the Google Play app icon, which keeps its transparent background because the spec allows it. Background removal results are not meant for direct store submission, so they download as transparent PNG; to use one as a store screenshot, process it again with store image editing.