Image Resizer
Type a width, height or percentage, and the resized image downloads instantly. Aspect ratio stays locked by default so nothing gets stretched. JPG, PNG, WebP, GIF. Nothing leaves your browser.
Input
Drop an image here
or click to browse: JPG, PNG, WebP, GIF
Settings
How to resize an image online
Upload, set the size, download. No account, no watermark, nothing installed.
- 01
Drop your image in
Drag it onto the tool or click to browse. JPG, PNG, WebP, GIF. Doesn't matter. Nothing gets sent anywhere; the whole thing runs in your browser.
- 02
Enter the target size
Type a width and the height adjusts automatically (aspect ratio is locked by default). Or enter a percentage: 50% halves both dimensions. If you need a specific width AND height that don't match the original ratio, turn the aspect-ratio lock off first. Just know it'll stretch.
- 03
Download
Click Resize. Same format comes back: JPG in, JPG out.
Why people resize images
Usually one of four reasons.
Social platforms reject wrong sizes
Instagram crops anything that isn't 1080×1080 for feed posts. Open Graph images get mangled if they're not 1200×630. Twitter/X headers need 1500×500. Get the dimensions right once and stop guessing why things look off.
Phone photos are enormous
A photo from a modern phone is 4–10 MB and often 4000px+ wide. Nobody needs that for an email or a web page. Resize to 1200px wide and it drops to under 400 KB: same visual result, fraction of the size.
Serving a 3000px image in a 600px slot
One of the most common causes of slow page loads. The browser downloads the full 3000px file and shrinks it in CSS. Resize to the actual display size before uploading and you cut the download by 80%+.
Inconsistent thumbnail grids
Product listings and blog cards look broken when images are different sizes. Resize everything to the same dimensions (400×300, 300×300, whatever your layout uses) before uploading.
Worked example: a phone photo for a website
A 12-megapixel phone photo is 4032 × 3024 pixels. Type 1200 as the width with the ratio lock on and the height becomes 900, keeping the same 4:3 shape. The new image has 1.08 million pixels instead of 12.2 million, about 9% of the original, so the file usually shrinks dramatically even before you lower the quality. That size is still sharp across a laptop screen, which is all most website layouts need.
Percentage mode does the same thing proportionally: 50% halves both sides and leaves a quarter of the pixels. Use pixels when a platform asks for an exact size, and a percentage when you just want the file smaller.
Sizes platforms commonly ask for
Uploading at the expected size avoids the platform's own cropping or blurry scaling:
| Use | Size in pixels | Shape |
|---|---|---|
| Instagram square post | 1080 × 1080 | 1:1 |
| Instagram portrait post | 1080 × 1350 | 4:5 |
| Link preview image (Open Graph) | 1200 × 630 | 1.91:1 |
| YouTube thumbnail | 1280 × 720 | 16:9 |
| Full-HD screen or slide | 1920 × 1080 | 16:9 |
If the photo's shape differs from the target, crop to the right ratio first with the Image Cropper, then resize. Turning the lock off and typing both numbers stretches the picture instead.
Limits worth knowing
- Making an image bigger can't add detail. Enlarging past the original size looks soft; the Image Upscaler is better for that.
- JPEG and WebP use the quality slider (10 to 100, starting at 92). PNG ignores it and stays lossless.
- Saving a transparent PNG as JPEG fills the transparent areas with white.
- One image at a time, and EXIF metadata such as GPS location isn't kept.
Frequently asked questions
WebP, AVIF, JPEG & PNG Compared
A technical comparison of modern image codecs, compression efficiency, lossy vs. lossless algorithms, and Core Web Vitals optimization.