On-Device vs Cloud AI Photo Editing: What Happens to Your Photos?
By the NextG Design team · Published 19 October 2026 · 3 min read
Quick answer: Most online AI photo editors upload your image to a server, process it there and send the result back; the photo may be logged, kept or used to train models, depending on the provider's policy. On-device AI editors instead download the AI model to your browser and run it locally with WebAssembly or WebGPU, so the photo never leaves your computer or phone. You can check by opening the browser's developer tools (Network tab) while editing: an on-device tool shows model downloads but no image uploads.
How cloud AI editors handle your photos
Large AI models need powerful hardware, so most AI editing websites and apps send your photo to a server. That's not automatically bad, but it means a copy of your image exists outside your device, at least temporarily. Things to look for in a privacy policy:
- Retention: how long uploads are kept (minutes, days, or until you delete your account).
- Training: whether images are used to “improve our services” — often meaning model training.
- Location: which country the servers are in, which affects your legal protections.
- Sharing: whether third-party AI providers process the images.
How on-device AI works in a browser
Browsers can now run neural networks efficiently. WebAssembly (with SIMD) runs compact models on the CPU — enough for background removal, inpainting, colourisation, depth estimation and face landmarks. WebGPU gives web pages access to the graphics card, fast enough for image generators with billions of operations, such as the SD-Turbo model behind Generative Fill. The model files are downloaded once and stored by the browser; after that, the editor can work without an internet connection.
| NextG Design AI tool | Model | Runs on | Download |
|---|---|---|---|
| Magic Eraser, Content-Aware Fill | MI-GAN | WebAssembly | ~28 MB |
| Background removal, Select Subject | ISNet | WebAssembly | ~40–80 MB |
| Colorize | DDColor | WebAssembly | ~62 MB |
| Lens Blur, Relight, Fog, 3D Photo | Depth Anything V2 (small) | WebAssembly | ~25 MB |
| Face Retouch, Face Swap, Red Eye | MediaPipe Face Landmarker | WebAssembly | ~4 MB |
| Generative Fill, Image Generator, Restyle | SD-Turbo (Stability AI) | WebGPU | ~2.6 GB |
How to check whether a tool uploads your photos
- Open the tool, then press F12 (or right-click › Inspect) and choose the Network tab.
- Run an AI edit.
- Look at the requests: model files (.onnx, .wasm, .task) are downloads to you. An upload shows as a POST request with a large request size, usually to an API address.
You can also switch off Wi-Fi after the model has loaded: an on-device tool keeps working, a cloud tool fails.
Trade-offs
- Speed: cloud GPUs are faster than most laptops for large models; on-device tools are faster for small ones because there's no upload.
- First use: on-device tools download the model once; large generative models can be gigabytes.
- Devices: generative AI needs WebGPU and a reasonably modern graphics chip; small models run on almost anything, including phones.
- Privacy and cost: on-device wins — no uploads, no accounts, no per-image charges.
Frequently asked questions
Do on-device AI editors work offline?
Yes, once the models have been downloaded. Load the editor and models while online, then you can edit without a connection.
Is it safe to edit ID documents with an online AI tool?
Only if it processes the image on your device or you trust the provider's retention policy. On-device tools never upload the document.
Why does on-device AI need a big download?
The model's weights must be on your device to run it there. Small models are tens of megabytes; image generators are a few gigabytes. They're stored by your browser so you only download them once.
What is WebGPU?
A modern browser standard that lets web pages use the graphics card for computation. It's what makes it possible to run image-generation models inside a browser.
Does NextG Design keep my photos?
No. Photos are processed in your browser and never sent to NextG Design. Unsaved work is autosaved only in your own browser's storage.
Try it free: the AI Photo Editor runs entirely in your browser — no upload, no account, no watermark.