4K Image Upscaler
Enlarge a low-resolution image using multi-step high-quality resampling plus edge sharpening — choose a straightforward 2x scale, or enhance toward full 4K (3840×2160). This is a genuine, carefully-tuned classical upscaling pipeline, not a generative AI model, so it sharpens and enlarges real detail rather than inventing new detail.
This upscaler uses multi-step high-quality resampling plus edge sharpening — a genuine, well-tuned classical algorithm. It is not a generative AI model: it sharpens and enlarges existing detail, it does not invent new detail. Results are best on images that are only moderately low-resolution.
Drag & drop your file here
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Supports .jpg, .jpeg, .png, .webp · Max 15 MB
How the upscaling works
Instead of stretching your image in one large jump (which produces visible blur), the tool enlarges it in repeated 2x steps using the browser's high-quality image resampler, then applies an unsharp-mask sharpening pass to counteract the softness that scaling naturally introduces.
What this tool can and can't do
It can meaningfully improve perceived sharpness and let you print or display an image larger than its original resolution. It cannot reconstruct detail that was never captured in the source photo — for that, only true generative AI super-resolution models can attempt to hallucinate plausible detail, and we don't claim to do that here.
Best results
Works best on images that are only moderately low-resolution to begin with. Extremely small or heavily compressed source images will still look soft after upscaling — upscaling amplifies existing detail, it doesn't replace what's missing.
Tips for the best result
- Start from the highest-resolution original you have — upscaling can't recover detail that was never captured.
- 2x is the safer choice for most images; 4K enhance is best for images already reasonably close to that resolution.
- If your source image has heavy JPEG artifacts, they will also be enlarged and sharpened along with real detail.
Frequently Asked Questions
Is this AI upscaling?+
No — it uses a classical multi-step resampling and sharpening pipeline, not a generative AI model. We're explicit about this so you know exactly what to expect: enhanced clarity, not invented detail.
Will this fix a blurry or low-quality photo?+
It can improve perceived sharpness somewhat, but it can't recover detail that was never captured or was destroyed by heavy compression.
Is my image uploaded to a server?+
No, all processing happens locally in your browser.
What image sizes are supported?+
JPG, PNG and WebP up to 15 MB. Very large source images may take longer to process.
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