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 icons, and promotional images. Upload a screenshot or design, pick a target device preset, adjust position and scale in the live preview, and export a correctly sized PNG — 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 asks for 6.7-inch iPhone screenshots (1290 × 2796) and accepts 6.5-inch (1242 × 2688) and 5.5-inch (1242 × 2208) sets for older devices, plus 13-inch iPad screenshots for tablet apps. Google Play is more flexible, but recommends 1080 × 1920 or higher for phone screenshots and enforces minimum and maximum dimensions at upload.

The device presets in the studio encode these requirements, so exported files pass store validation as they are. Pick the preset matching each device your app targets, and reuse the same source image across presets — the studio keeps your position and scale adjustments per preset.

Getting better results

• Start from the highest-resolution source you have — upscaling a small screenshot always loses sharpness.
• Match orientation: use portrait sources for portrait presets. Rotating or heavy cropping in the preview costs pixels.
• Background removal works best when the subject clearly contrasts with the background; busy backgrounds may need a retouch afterwards.
• Leave breathing room around important text — store listings crop and frame screenshots differently across devices.

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. Exports are PNG files — the format both stores accept for screenshots and icons.

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.