Upscale images 4× with AI that never sees them
Free online image upscaler: 4×, no signup, no watermark, runs in your browser. Real-ESRGAN does the work on your device; when you’re signed out and using on-device mode, your photos are never uploaded.
Drop an image here, or paste from clipboard
Formats & privacy
PNG · JPEG · WebP · HEIC · TIFF. Signed out, on-device processing never uploads your images. Signing in saves your images online in your library.
WebGPU accelerated~5 MB model, cached locallyLossless PNG out
How it works
Drop an image
Signed out, on-device processing never uploads your images. Signing in saves your images online in your library.
AI rebuilds the detail
Real-ESRGAN processes the image in 192-pixel tiles on your GPU, inferring realistic texture at 4× the resolution.
Download the 4× PNG
800×600 becomes 3200×2400. Watch the before/after slider, then save the lossless result.
Curious what "AI upscaling" actually does? Read the plain-English guide.
Everything you'd pay for elsewhere, free
Private by architecture
Signed out, on-device processing never uploads your images. Signing in saves your images online in your library.
Free and unlimited
No credits, no daily quota, no account. Your own GPU does the work, so we don't need to charge for compute.
WebGPU accelerated
Runs on your graphics card via WebGPU where available. In our tests a 1-megapixel photo finishes about 6× faster than the multi-threaded CPU fallback.
Real-ESRGAN quality
The same open-source super-resolution model used by professional tools, rebuilding texture instead of just stretching pixels.
Works offline
After the first online upscale the app and its 5 MB model are cached. Load the page, go offline, keep upscaling.
PNG, JPEG or WebP out
Download the 4× result as a lossless PNG, a JPEG or a WebP, or a 2× version of any of them: no watermarks, no strings.
Why on-device beats the cloud
Most online upscalers send your image to a server farm, run the model there, and send the result back. That architecture is why they need accounts, quotas, and privacy policies with teeth. Doing the same work on your own hardware makes those problems disappear.
| Typical cloud upscaler | On this device, signed out | |
|---|---|---|
| Your image travels | To their servers and back | Nowhere, it stays in the tab |
| Cost | Free trial, then credits | Free, unlimited |
| Limits | Daily quotas, queue times | Only your device's memory |
| Account required | Usually, for full size | Never |
| Watermarks | Common on free tiers | None |
| Privacy promise | "Auto-deleted after 24 to 72 hours" | Nothing to delete, no upload |
Questions, answered
Curious what "AI upscaling" actually does?Read the plain-English guide
Is this image upscaler really free?
Yes. It's a free online image upscaler: 4×, no signup, no watermark, runs in your browser. It's also unlimited, with no credits. The AI runs on your own hardware instead of our servers, so serving the tool costs almost nothing and there's nothing to meter. An optional free account keeps your results in a library; it costs nothing either.
Are my images uploaded to a server?
No. The neural network runs inside your browser using WebGPU (or WebAssembly as a fallback). Without an account, your image is never transmitted anywhere. You can verify this in your browser's network inspector, or complete an on-device upscale online, then upscale with Wi-Fi turned off. Signing in to the optional free account is the exception: your finished upscales are then saved to that account so you can open them later, and Cloud HD, an optional mode for accounts, uploads the file you pick for it and processes it in the cloud.
What AI model does it use?
Real-ESRGAN (the realesr-general-x4v3 variant), a widely used open-source super-resolution network, running via ONNX Runtime Web. The model itself is only about 5 MB and is cached by your browser after the first online upscale.
How big can my image be?
Output is limited by your device's memory, since 4× upscaling multiplies pixel count by 16. On desktop the input limit is about 6 megapixels (e.g. 3000×2000); on phones about 2 megapixels. Larger images are reduced to fit automatically before upscaling. Accepted inputs: PNG, JPEG, WebP, GIF, BMP, AVIF, HEIC and TIFF. Files up to 250 MB on a computer and 120 MB on a phone are accepted.
Which browsers are fastest?
Recent Chrome, Edge, and Safari use WebGPU, which in our tests runs larger images around 6× faster than the WebAssembly fallback. Every modern browser works; the tool automatically picks the fastest engine your device supports.
Does it work on photos of people?
Yes, though the general-purpose model doesn't include a dedicated face-restoration pass. It excels at photos, artwork, game textures, logos, and old low-resolution images. Heavily compressed faces may keep some softness.
What format is the result?
Your choice of lossless PNG, JPEG or WebP, at 4× the original width and height (800×600 becomes 3200×2400) or at 2×. A before/after slider shows the result against the original before you save. Everything happens locally, so the download is instant once processing finishes.
What if I need more than 4×, face restoration, batch, or video?
The free tool does one job: a single image, 4×, on your device. For 8×, video up to 4K or batches of up to 50 images, Cloud HD, an optional mode for accounts, runs a larger model in the cloud and uploads the file you pick for that job. For a dedicated face enhancer or batch folders, Topaz Gigapixel is the desktop option (paid, Windows and Mac). Nothing here changes: the free tool stays free, unlimited and on-device.
Ready when you are
Signed out, on-device processing never uploads your images. Signing in saves your images online in your library.
Upscale an image