FastImageToolsFastImageTools

Upscale an Image to 4K Online

Target 3840 px on the longest side without forcing the image into a 16:9 canvas.

PNG resultUp to 4×Batch supported

Drag & drop your images

or click below to browse your files

JPGJPEGPNGWebPHEICHEIFBMP
⌘VPaste from clipboard
•Drag from Finder or Photos

Free users: up to 15 images at once • Premium: unlimited batch processing

Back to Upscale Images Online with AI

Prepare a larger image for 4K-sized displays

This preset is useful when you need a larger source for a 4K screen, slide, wallpaper, or video layout while keeping the original aspect ratio.

Here, 4K means a 3840 px longest-side target. The tool preserves the source aspect ratio; it does not create a fixed 3840×2160 canvas or invent missing detail.

How to enlarge an image

  1. 1

    Add your images

    Select one or more supported image files.

  2. 2

    Review the target size

    The custom target is set to 3840 px on the longest side. Enlargement remains capped at 4×, so very small sources may finish below 3840 px.

  3. 3

    Save the enlarged image

    Run the tool, preview the result, and download the PNG output.

Frequently asked questions

Will upscale image to 4k recreate missing detail?

Here, 4K means a 3840 px longest-side target. The tool preserves the source aspect ratio; it does not create a fixed 3840×2160 canvas or invent missing detail.

Can I enlarge several images together?

Yes. Add multiple supported files and process them in one batch. The same size rules and 4× limit apply to each image.

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Enlarge PNG pixel dimensions and download a PNG result

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