Image Resizer
Scale images by exact pixel dimensions or percentage with aspect ratio lock, fit options, and real-time preview.
Resize without losing the shape you need
Use the aspect lock to keep the original proportions. Unlock it when you need a specific box, then choose whether to crop to fill, add space around the image or stretch it. Enlarging an image adds pixels, not missing detail.
Example: resize a photo for a website
You need a smaller photo or a specific banner size. Set the dimensions first, then choose whether to keep or trim the edges.
- Choose the dimensions: Enter a width or height in pixels. Use a percentage button or enter a custom percentage to scale both dimensions together.
- Keep the shape, or unlock it: Keep the aspect lock on for the original proportions. Unlock it when your destination requires a different-shaped box.
- Check how the image fits: Crop to fill trims the edges. Pad keeps the full image and adds space. Stretch forces the image into the box and may distort it. The preview updates as you change these options.
- Save the format you need: Choose JPEG for a white background, or PNG or WebP when you want transparency. Click Resize Image, then download and inspect the actual dimensions.
Understanding Fit Modes and Upscaling Limitations
When width and height are adjusted independently, fit modes determine how the image conforms to the new frame. Contain preserves all pixels and adds background fill if aspect ratios differ. Cover fills the entire frame by cropping excess edges. Stretch forces the image into the exact dimensions, which can distort proportions. Note that while downscaling produces sharp results, upscaling a small image cannot recreate missing optical details.
Common questions
What is the difference between resizing and compressing?
Resizing changes the actual number of pixels (width and height). Compressing alters how efficiently pixel data is encoded to reduce file size in kilobytes, which can be done with or without changing dimensions.
How do I prevent my image from looking stretched?
Keep the Lock Aspect Ratio toggle enabled. This ensures proportional scaling so faces, text, and objects retain their natural proportions.
Can I make a low-resolution image high-resolution?
Upscaling increases the pixel count using interpolation, which helps avoid pixelated blocks, but it cannot restore fine details that were not present in the original capture.
Are my images processed on a server?
No. All scaling and canvas operations execute locally in your browser memory via HTML5 Canvas. Your files remain on your device.
Can I keep a transparent background?
Yes. Choose PNG or WebP and select Transparent under Background. JPEG does not support transparency, so its background is white. Padding can also be transparent when you choose a compatible format.
How do I prepare a resized image for an online form?
Check the required format and file-size range as well as the pixel dimensions. Our online-form image workflow shows how to combine resizing with conversion or compression while preserving the final dimensions.