What the image resizer does
The resizer changes an image's pixel dimensions — by entering an exact width and height, or by a percentage of the original — and saves the result as JPG, PNG or WebP. Aspect ratio is locked by default so the picture is not stretched; enter one dimension and the other follows. Resizing is done by the browser's canvas, which uses high-quality interpolation, and nothing is uploaded.
Pixels vs percentage
- Pixels — when a destination has a known requirement: a 1,200 × 630 social preview, a 512 × 512 app icon, a 1,920-wide hero image.
- Percentage — when you just need something smaller and do not care about exact numbers: 50% halves each dimension and cuts the pixel count to a quarter; 25% cuts it to a sixteenth.
Enlarging is possible but rarely wise. Scaling up invents pixels by interpolation, producing a soft image; a 2× enlargement is usually acceptable, 4× is visibly blurry. For real upscaling use a dedicated AI upscaler.
Common target sizes
| Use | Size (px) | Aspect ratio |
|---|---|---|
| Open Graph / link preview | 1200 × 630 | 1.91:1 |
| Instagram feed (square / portrait) | 1080 × 1080 / 1080 × 1350 | 1:1 / 4:5 |
| Instagram story, TikTok, Reels | 1080 × 1920 | 9:16 |
| YouTube thumbnail | 1280 × 720 | 16:9 |
| X (Twitter) header | 1500 × 500 | 3:1 |
| LinkedIn banner | 1584 × 396 | 4:1 |
| Full-width web hero | 1920 × 1080 (or 2560 wide for retina) | 16:9 |
| Blog inline image | 1200–1600 wide | any |
| Email image | 600–800 wide | any |
| Favicon / app icon | 512 × 512 (scaled down by the platform) | 1:1 |
| Passport photo (US) | 600 × 600 | 1:1 |
Resize, crop or both?
Resizing scales the whole image; it cannot change the aspect ratio without distortion. If the target shape differs from the original — a 4:3 photo going into a 16:9 slot — crop first to the right shape with the Image Cropper, then resize to the exact pixel size. Doing it in that order avoids stretching and keeps the part of the picture you care about.
How much resolution do you need?
- Screens: a 1,600-pixel-wide image fills a laptop display and looks sharp on phones. Retina and 4K displays benefit from 2× that, at the cost of four times the pixels.
- Print: 300 pixels per inch is the standard. A 6 × 4 inch print needs 1,800 × 1,200 px; an A4 page needs about 2,480 × 3,508 px. Resizing below that for print will show softness.
- Thumbnails: 200–400 px wide. Anything larger is wasted bandwidth.
What changes besides dimensions
- File size falls roughly with pixel count: halving width and height cuts size to about a quarter.
- EXIF metadata is removed, including GPS location — usually welcome when sharing.
- Transparency is kept in PNG and WebP output; JPG fills transparent areas with white.
- Animated GIFs lose their animation; only the first frame is resized.