4K Image Upscaler

Turn small photos and art into sharp 4K, 5K or 8K images with real AI, right in your browser. For a quick 2x-4x enlargement use the Image Upscaler, and fix dull colours first with the Image Enhancer.

Real AI 4K, 5K, 8K Nothing uploaded Try a sample:
Related Tools
Image Upscaler Image Enhancer Image Resizer GIF Upscaler Compress JPG

How to upscale an image to 4K

  1. Add your image. Drop an image into the box, browse for it, or paste it with Ctrl+V. PNG, JPG, WebP, AVIF, BMP and GIF work.
  2. Pick the resolution. Choose Full HD, 2K, 4K, 5K or 8K. Fit keeps the whole picture; Fill crops it to the exact size.
  3. Choose the image type. Photo for camera pictures, Anime & art for drawings and illustrations.
  4. Upscale and download. Press Upscale, compare before and after with the slider, choose JPG, PNG or WebP and download.

Your image never leaves your device - the AI runs in your browser.

4K, 5K and 8K sizes

NamePixelsMegapixelsGood for
Full HD1920 x 10802.1 MPWebsites, social media, laptop screens
2K (QHD)2560 x 14403.7 MPGaming monitors, phone wallpapers
4K UHD3840 x 21608.3 MPTVs, desktop wallpapers, A4 prints
5K5120 x 288014.7 MPiMac and Studio Display wallpapers
8K UHD7680 x 432033.2 MPBig prints, posters, 8K screens

Fit gives the long side of your picture this length and keeps all of it. Fill crops it to exactly this size, so it fills a screen with no bars.

Portrait images are turned around automatically - for example 2160 x 3840 for a 4K phone wallpaper.

How the AI reaches 4K and 8K

Real-ESRGAN enlarges an image 4x in one pass and rebuilds edges and textures while doing it. A 960 x 540 picture becomes 4K in one pass.

Smaller pictures need more than 4x. With Max detail, the result of the first pass goes through the AI a second time, so a 480 x 270 thumbnail can still become a crisp 8K image. Fast uses one pass and smooth resizing for the rest.

AI cannot recover details that were never in the photo, but it gives a far cleaner result than stretching pixels. For animations, use the GIF Upscaler.

Tips for the best result

  • Start from the original. The least-compressed copy you have gives the cleanest 4K result.
  • Only want the scene? Brush away buttons, titles, logos or game HUD in the Watermark Remover first - there is a one-tap link once your image is loaded.
  • Crop first. Cutting away what you do not need makes the AI faster - use the Image Cropper.
  • Fix light and colour before upscaling in the Image Enhancer.
  • Use a graphics card. Recent Chrome and Edge run the AI with WebGPU - many times faster than the processor.
  • Sharing online? Save as JPG or WebP, or shrink the file with Compress JPG.

Frequently Asked Questions

Drop your image into the box, keep 4K selected and press Upscale to 4K.

The AI rebuilds detail while it enlarges your picture, then you can compare before and after and download it as JPG, PNG or WebP.

4K UHD is 3840 x 2160 pixels, 5K is 5120 x 2880 and 8K UHD is 7680 x 4320.

With Fit, the long side of your image gets that length and the whole picture is kept. With Fill, the image is cropped to exactly that size - ideal for wallpapers.

Real AI. The tool runs Real-ESRGAN, a neural network that rebuilds edges, textures and fine detail.

Small images that need more than 4x get two AI passes on the Max detail setting, so even 8K results stay sharp. For quick 2x-4x enlargements there is also the Image Upscaler.

No. Everything runs in your browser - the AI model is downloaded once (about 5 MB) and your pictures never leave your device.

There are no upload limits and nothing is stored on a server.

With a graphics card (WebGPU, in recent Chrome and Edge) a 4K result usually takes seconds to a minute. Without one the AI runs on the processor and can take several minutes - the Fast setting helps.

The page shows an estimate before you start and the time left while it works.

Photo for camera pictures, portraits, products and screenshots. Anime & art for drawings, illustrations, cartoons and game art - it keeps lines clean and is about twice as fast.

Yes. At 300 DPI, a 4K image prints at about 33 x 18 cm (13 x 7 in) and an 8K image at about 65 x 37 cm (26 x 14 in).

For an exact print width in cm or inches, saved DPI, hard edges and a white ink mask, use the Image Upscaler.

Yes, in PNG and WebP. The AI upscales the cut-out edges too, so logos and stickers stay crisp on dark or light backgrounds.

Images up to 25 megapixels go through the AI at full size, so you can also take an earlier result to 8K.

A 4K picture has over 8 million pixels, so PNG files can be 10-30 MB. JPG or WebP at quality 90 look the same and are many times smaller.

The real file size is shown after upscaling, and you can switch format without running the AI again. Need it even smaller? Use Compress JPG.

AI upscaling uses the Real-ESRGAN models by Xintao Wang et al. (BSD 3-Clause), running with ONNX Runtime Web.

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