Upscale Images to 4K — Free and Private
Enlarge any image to 4K with sharper edges and less noise. Everything runs on your device — nothing is uploaded.
- No upload
- No sign-up
- No watermark
Drop images here, paste, or browse
JPG, PNG, WebP or AVIF, up to 10 at a time. Your images never leave this device.
How it works
Three steps, all on your own device.
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Step 1: Add images
Drop, paste or pick up to 10 images: JPG, PNG, WebP or AVIF, up to 20 MB each. They are read straight from your disk and never sent anywhere.
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Step 2: Choose size, sharpness and cleanup
4K makes the long side 3,840 px and 2K makes it 2,560 px, or pick 2× or 4×. Set the amount of sharpening and whether to clean up noise and JPEG artifacts.
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Step 3: Compare and download
Check the result against the original at 100%, then download each image, or the whole batch as a ZIP, as JPG, PNG, WebP or AVIF.
Why 4K Images
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Private by design
Your images are processed inside your browser and never leave your device. There is no upload step and no server that could receive them.
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Free, no sign-up, no watermark
No account, no trial and no paid plan. Nothing is stamped on the result.
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Sharper than a normal resize
Edge-aware upscaling keeps lines and outlines crisp, and adaptive sharpening adds definition without boosting noise in flat areas. It does not invent detail that is not in the original.
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Batch, ZIP and modern formats
Queue up to 10 images, download them one by one or as a ZIP, and save as JPG, PNG, WebP or AVIF.
Frequently asked questions
Is it free?
Yes. There is no account, no paid plan and no watermark on the results.
Are my images uploaded?
No. Images are decoded, enlarged and saved inside your browser. The site has no upload endpoint, so your files never leave your device.
Will it make a blurry photo sharp?
It makes edges crisper and can reduce noise and JPEG blockiness, so the enlarged image looks cleaner than a normal resize. It cannot recreate detail that was never captured: a blurry photo stays soft, just larger and cleaner.
What sizes can I produce?
4K makes the long side 3,840 px and 2K makes it 2,560 px, keeping the aspect ratio. Images that are already that large are skipped, never shrunk. 2× and 4× multiply both sides up to what your device can hold in memory: about 16.7 megapixels on iPhone and iPad and about 33.5 megapixels on most computers. If a size is too large, the tool tells you what it will produce instead before it starts.
Which formats are supported?
You can add JPG, PNG, WebP and AVIF images, and HEIC if your browser can open it. Results can be saved as JPG, PNG, WebP or AVIF. Auto picks JPG for photos and PNG for images with transparency.
Can I use the results commercially?
Yes. The images are yours, and we claim no rights to them or to the results.
Why is it slower on my phone?
All processing happens on your own device, so speed depends on its processor, graphics chip and memory. Phones have less of each than most computers, and large outputs or AVIF files take longer to produce.
Ready to upscale an image?
Add an image and download a 4K version. No account, no upload.