How to use the Image Resizer
- Drag the photos you want to resize onto the area above, or click it to choose files. You can add several photos at once.
- Pick an Instagram, YouTube thumbnail, ID photo or passport photo size from Common sizes, or type a width and height in pixels. If you enter only one value, the other is calculated from the original aspect ratio.
- To shrink photos by a set amount, switch the unit to Percent (%) and move the slider.
- Click Resize. Then use the save button under each preview, or click Download all as ZIP.
Pixels and file size: what happens when you shrink a photo
Image size is given as width × height in pixels. A 4000×3000 photo has 12 million pixels (12 MP). Resize it to 2000 px wide and you get 2000×1500, or 3 million pixels. That is one quarter of the pixels, and the file size usually drops by roughly the same proportion.
A width of 1920 px is plenty for viewing on a monitor or phone screen. Images in the body of a blog post or web page usually look sharp at 800–1,200 px wide. If the file is still too large after resizing, adjust the quality with the image compressor.
Instagram, YouTube thumbnail, ID and passport photo sizes
| Use | Size in pixels | Aspect ratio |
|---|---|---|
| Instagram square post | 1080 × 1080 | 1:1 |
| Instagram portrait post | 1080 × 1350 | 4:5 |
| YouTube thumbnail | 1280 × 720 | 16:9 |
| Full HD wallpaper | 1920 × 1080 | 16:9 |
| ID photo 3×4 cm, 300 dpi | 354 × 472 | 3:4 |
| Passport photo 35×45 mm (UK, Australia, EU and others), 300 dpi | 413 × 531 | 7:9 |
| US passport photo 2×2 in, 300 dpi (enter as a custom size) | 600 × 600 | 1:1 |
To convert a print size to pixels, use pixels = inches × dpi, or for metric sizes pixels = cm ÷ 2.54 × dpi. Print work is usually based on 300 dpi, so 2 inches is 2 × 300 = 600 px and 3 cm is 3 ÷ 2.54 × 300 ≈ 354 px. If the place you're submitting to sets its own pixel dimensions or file size limit, follow those rules first.
Keep ratio, crop from center, or stretch?
- Keep aspect ratio (fit inside): shrinks the photo, at its original proportions, until it fits inside the width × height box you entered. Nothing is cropped or distorted, but one side of the result may come out smaller than the number you entered.
- Match ratio and crop from center: trims whatever doesn't fit, measured from the center, so the result is exactly the size you entered. Use this when you need a fixed format such as a square post or an ID photo.
- Stretch to exact size: ignores the aspect ratio and forces the image to the size you entered. If the ratio differs from the original, faces can look too wide or too tall, so be careful.
Enlarging a small photo can't add detail that was never there, so it gets blurry. You'll get the best results by starting from the original and making it smaller, not bigger.
Choosing an output format
JPG works best for photos and keeps files small. PNG is lossless and keeps transparency, which suits logos, screenshots and graphics. WEBP usually gives smaller files than JPG at similar quality and works in all modern browsers. The quality slider applies only to JPG and WEBP. A setting of around 80–90% is a good balance for most photos.