Image Resizer
Resize images to any dimension
100% free. Runs entirely in your browser - your files and data never leave your device and nothing is uploaded to any server.
4K UHD selected — upload an image to apply it.
Drag & drop files here
or browse to upload
Supports PNG, JPG, WebP up to 20MB
Processed in your browser - your file never leaves this device.
About this tool
A 4K UHD image is 3840 by 2160 pixels - the native resolution of most modern TVs, many laptops with high-density screens, and 4K video timelines. People resize to it for wallpapers, digital signage, video title cards and stills dropped into a 4K edit, where anything smaller is visibly upscaled on a large screen. This page crops to that 16:9 frame as soon as you add a picture. It is four times the pixels of 1080p, and roughly four times the file size, so check before emailing one.
How to use this tool
- Start from a large originalUse the highest-resolution photo you have - a small image stretched to 4K looks soft on a big screen.
- Frame the 16:9 cropDrag the image so the important part sits inside the 3840 x 2160 frame shown in the preview.
- Export for the screenSave as JPG for photos or PNG for graphics with text, then copy it to the TV, display or video timeline.
Where 4K images are actually used
A 4K frame holds 8.3 million pixels, so a JPG at high quality is typically a few megabytes. For video work, match the frame exactly to avoid your editor rescaling it; for signage, check whether the player expects landscape or a rotated 2160 by 3840 portrait frame.
- Desktop and TV wallpapers for 4K monitors and smart TVs.
- Title cards, lower thirds and stills inside a 4K video project.
- Digital signage and lobby screens, which are often 4K panels.
- Presentation backgrounds shown on large conference-room displays.
Key features
- The native resolution of most modern TVs and 4K monitors.
- A clean 16:9 frame for wallpapers, signage and 4K video edits.
Common uses
- Making a 4K desktop wallpaper.
- Exporting stills for a 4K video edit.
- Preparing artwork for a lobby screen.
Tips for better results
- Start from a source at least 3840 pixels wide.
- Use JPG for photos to keep the file manageable.
- Check whether signage players want a portrait frame.
Mistakes to avoid
- Upscaling a 1080p image and expecting 4K detail.
- Saving a 4K photo as PNG and ending up with a huge file.
Frequently asked questions
3840 x 2160, about 8.3 megapixels - four times 1080p.
Yes, for consumer screens. Cinema 4K (DCI) is slightly wider at 4096 x 2160.
Most recent phone cameras capture more than 3840 pixels across, so yes - crop to 16:9 first.
Four times the pixels of 1080p, which is also four times the file size - worth checking before you attach one to an email.
Drop it onto this page. The 4K UHD preset is already selected, so it resizes straight to 3840 x 2160 pixels and shows the crop before you download.