How to use the Image Resizer
- Drop one or more images onto the box, click it to choose files, or paste a screenshot with Ctrl+V.
- Type a new width or height with Keep aspect ratio on, switch to By percentage, or click a preset size.
- If you set both sides to a shape that differs from your photo, choose Crop to fill, Fit with background or Stretch.
- Pick an output format and quality, then download each image or click Download all for a ZIP.
Features
- Resize by exact pixels or by percentage
- Aspect-ratio lock that works across a mixed batch
- One-click presets for posts, HD video and link previews
- Crop-to-fill, fit-with-background or stretch for exact sizes
- Sharp downscaling in halving steps instead of one big jump
- Batch download as a single ZIP file
Pixels, percentages and aspect ratio
A digital image is a grid of pixels, and its size is written as width × height. A photo from a 12-megapixel phone camera is usually 4032 × 3024 pixels. The aspect ratio is the width divided by the height, so that photo is 4:3. Keeping the ratio while resizing is what stops faces and logos from looking squashed.
The formula is simple: new height = new width × (original height ÷ original width). Resize the 4032 × 3024 photo to 1200 pixels wide and the height becomes 1200 × 3024 ÷ 4032 = 900, giving 1200 × 900. With Keep aspect ratio switched on, the tool does this math for every image in your batch, even if some are landscape and some portrait. The side you typed last is the one that stays fixed.
Percentage mode multiplies both sides by the same factor. At 50%, a 4032 × 3024 photo becomes 2016 × 1512, which is only a quarter of the original pixel count, so the file size drops sharply.
When the new shape is different
Many platforms ask for an exact size, such as a 1080 × 1080 square. A 4:3 photo cannot fill a square without changing something, so you choose how:
- Crop to fill scales the photo until it covers the whole frame and trims the overflow evenly from both sides. Our 4032 × 3024 example is scaled to 1440 × 1080, then 180 pixels (12.5%) are trimmed from the left and the right.
- Fit with background shows the entire photo and fills the empty bands with a color you pick, like letterboxing on a TV.
- Stretch forces the photo into the frame and distorts it. It is only useful for textures and abstract graphics.
If you need to choose exactly what stays in the frame, use the Image Cropper first, then resize.
Common image sizes
| Use | Size (px) | Ratio |
|---|---|---|
| Square social post | 1080 × 1080 | 1:1 |
| Portrait feed post | 1080 × 1350 | 4:5 |
| Story, Reel or Short | 1080 × 1920 | 9:16 |
| Full HD screen or slide | 1920 × 1080 | 16:9 |
| Video thumbnail | 1280 × 720 | 16:9 |
| Link preview (Open Graph) | 1200 × 630 | about 1.91:1 |
For more platform sizes in one place, try the Social Media Image Resizer.
Resizing images for websites
Size images to the largest width they will actually be displayed at, multiplied by the screen's pixel density. A picture shown in a 600-pixel-wide column looks crisp on a high-density phone or laptop at 1200 pixels wide. Anything larger only adds download time. Because file size grows with the number of pixels, halving both sides typically removes around three quarters of the data, even before you compress the image.
Tips for the best quality
- Shrinking is safe; enlarging is not. Upscaling spreads existing pixels over a bigger area and cannot invent detail, so text and edges turn soft.
- This tool shrinks large images in halving steps before the final size, which keeps fine detail sharper than a single big jump.
- Keep your original files. Resize copies for each purpose instead of resizing the same file again and again.
- Choose PNG for screenshots and graphics, and JPG or WebP at 80–90% quality for photos.
Frequently asked questions
Does resizing an image reduce its quality?
Making an image smaller removes pixels, but the result looks just as sharp at its new size. Making it larger cannot add detail, so enlarged images look softer. Saving as JPG or WebP also adds a little compression, which is invisible at 85–90% quality.
How do I resize a photo without stretching it?
Keep the aspect ratio lock on and type only a width or only a height. If you need an exact size with a different shape, choose Crop to fill or Fit with background instead of Stretch.
Can I resize many images at once?
Yes. Add as many images as you like and they are all resized with the same settings. With the ratio locked, each image keeps its own proportions. Download them one by one or together as a ZIP file.
Are my photos uploaded anywhere?
No. Resizing happens inside your browser using your device’s own image engine, so your photos never leave your computer or phone.
What is the difference between resizing and compressing?
Resizing changes the number of pixels (the dimensions). Compressing keeps the dimensions and stores the pixels more efficiently. For the smallest files, resize to the size you need and then use the Image Compressor.