How it works
How to resize an image
- Add your images. Drag them in or tap the box. JPG, PNG, WebP and iPhone HEIC all work, and you can resize many at once.
- Choose how to measure. Pixels for screens and websites, percentage to scale, or centimeters, millimeters and inches for printing.
- Enter the size. Leave height empty to keep the original proportions. If you enter both, choose whether to fit inside, crop to fill, or stretch.
- Resize and download. Optionally set a maximum file size in KB if a form has an upload limit.
What DPI means for printing
Pixels, centimeters and DPI explained
Screens measure images in pixels. Printers measure them in physical units like inches or centimeters, and DPI (dots per inch) connects the two: pixels = inches × DPI.
| Print size | At 300 DPI | At 150 DPI |
|---|---|---|
| 2 × 2 in (51 × 51 mm) | 600 × 600 px | 300 × 300 px |
| 35 × 45 mm | 413 × 531 px | 207 × 266 px |
| 4 × 6 in | 1200 × 1800 px | 600 × 900 px |
| A4 (210 × 297 mm) | 2480 × 3508 px | 1240 × 1754 px |
300 DPI is the usual standard for sharp photo prints. When you resize in cm, mm or inches as a JPG, this tool also writes the DPI into the file so it prints at the right size.
Common image sizes
| Use | Size |
|---|---|
| Social sharing / link preview image | 1200 × 630 px |
| Instagram square post | 1080 × 1080 px |
| YouTube thumbnail | 1280 × 720 px |
| Full HD website banner | 1920 × 1080 px |
| Blog content image | 1200 px wide |
Platforms change their recommended sizes from time to time, so check their current guidelines for anything critical.
Tips for the sharpest results
- Making an image smaller keeps it sharp. Making it much larger than the original can't add detail and will look soft.
- Use Crop to fill for profile pictures and thumbnails so there are no empty bars.
- Use PNG for logos and screenshots, and JPG or WebP for photos.
Frequently asked questions
How do I resize an image without losing quality?
Shrinking an image keeps it sharp. Keep the proportions locked (leave height empty), use quality-preserving formats like PNG or high-quality JPG, and avoid enlarging far beyond the original size.
How do I resize a photo to a specific size in cm?
Choose Centimeters, enter the width and height, and keep DPI at 300 for printing. The tool converts to pixels and saves the DPI in JPG files.
Can I resize multiple images at once?
Yes. Add several images and they're all resized to the same settings, each with its own download button.
What does “Fit inside” vs “Crop to fill” mean?
Fit inside keeps the whole image and fills any empty space with your background color. Crop to fill covers the whole frame and trims the edges that don't fit.
Are my photos uploaded?
No. Everything happens in your browser on your own device. Your photos are never sent to a server.
Does it work on my phone?
Yes. It works in modern browsers on iPhone and Android — tap the upload box to pick a photo from your gallery.