A browser-native instrument for upscaling photographs at 2× and 4×. Detail that was always there, waiting beneath the pixels.
Your files never leave your device. No upload. No queue. No server sniffing your private JPEGs while it "processes" them.
Drag a JPG, PNG, or WebP onto the instrument — or click to browse. Up to 20 MB. The file stays on your machine.
Select 2× or 4× magnification. The browser reconstructs each pixel locally — you can watch the elapsed time in the readout panel.
Compare before/after with the slider, then export as a full-resolution PNG. No watermark, no signup, no limit on how many times you use it.
Most "AI upscalers" hallucinate. They invent eyelashes where none existed, sculpt skin into plastic, turn freckles into noise. That is not reconstruction. That is fabrication.
Halo Optics v1 uses a high-quality bicubic kernel — conservative, faithful, and already sharper than most browsers deliver by default. Version 2, shipping soon, loads a quantised Real-ESRGAN ONNX model inside your browser via WebGPU.
Either way, the photograph never leaves your machine. The math runs on your silicon. The output is yours the instant it finishes.
Files never leave your browser. Zero network requests. Verify it yourself in DevTools.
No upload queue, no waiting. Processing starts the moment you drop a file — typically under 2 seconds.
No credits, no daily limits, no "free tier". Unlimited upscales, unlimited downloads, forever.
Works on Chrome, Safari, Firefox, Edge. Desktop or mobile. No app to install, no plugin to enable.
Drop JPG, PNG, WebP, or BMP. Output is always a lossless PNG at full resolution — ready for print or screen.
Your output is clean. No branding, no overlay, no "made with" badge. Use it commercially, personally, however you want.
Built on WebGPU, Canvas API, and open-source ONNX models. No proprietary black box. Inspect the source anytime.
Designed for photographers who work in dim environments. Low-glare, high-contrast interface that respects your calibrated monitor.
Every computation happens inside your browser tab. The photograph never touches a server — not ours, not anyone's. Close the tab and it is gone.
v1 ships with high-quality bicubic resampling. v2 loads a quantised Real-ESRGAN ONNX model directly in the browser via WebGPU — no cloud roundtrip.
No signup, no watermark, no credit system, no "Pro tier unlocks 4×". The instrument is yours the moment this page finishes loading.
Yes. Open the browser's network tab and watch: the file is never transmitted. The decoding, upscaling, and re-encoding all run inside your tab's sandbox. We could not see your photograph even if we wanted to.
Soft limit of 20 MB. Larger files work on desktop but may stall on phones. For photographs above 40 megapixels, use a desktop browser with at least 4 GB of free RAM.
For photographs with natural grain, yes — you will get clean, faithful enlargement without AI hallucinations. For illustrations, faces you want "enhanced", or heavy restoration work, wait for v2's Real-ESRGAN model.
Possibly — for batch processing, cloud-side larger models, or a desktop app. The core browser instrument will stay free forever. No retroactive paywalls.
More browser-native tools — same privacy promise, same zero-cost model. Each runs entirely on your device.
"Finally an upscaler that doesn't make my photos look like they were painted by an AI. Clean, fast, and I don't have to upload to some random server."
"I use this daily to upscale thumbnails and product shots for our Shopify store. The fact that it's completely free and works offline is incredible."
"Tried it for upscaling old family photos — 4× on a 640×480 shot looks genuinely sharp. No artifacts around faces, which is rare for a free tool."