Image Resizer
Resize JPG and PNG images to exact dimensions.
Free online image resizer
ToolAlto's free Image Resizer lets you resize an image online by entering an exact width and height in pixels. It works with browser-supported image files and processes the image in your browser.
Resize an image when a website, profile, form, document, or social platform requires specific dimensions. For example, you can turn a large image into a smaller 1200 × 800 image or prepare a file for a fixed-size upload field.
How to resize an image online
- Choose an image from your device.
- Enter the desired width and height in pixels.
- Select Resize image.
- Download the resized image.
Resize an image to exact dimensions
This tool uses the exact width and height you enter. If the new dimensions have a different aspect ratio from the original, the image may appear stretched or squashed. To avoid distortion, calculate or choose dimensions that keep the original aspect ratio.
Resize or compress?
Resizing changes an image's pixel dimensions. Compression changes how image data is stored and can reduce file size. If you need both smaller dimensions and a smaller file, resize first and then use the Image Compressor.
For a step-by-step explanation, read How to Resize an Image to Specific Dimensions and How to Compress Images Without Losing Quality.
JPG vs PNG when resizing
PNG input stays PNG, which helps preserve transparency. JPEG and other supported image inputs are saved as JPEG. The best format depends on the image: JPG is commonly used for photos, while PNG is useful for screenshots, logos, graphics, and transparency. See JPG vs PNG: Difference, Quality, and Which to Use for more guidance.
Supported output
JPEG images are saved as JPEG, PNG images remain PNG so transparency can be preserved, and other browser-supported image types are saved as JPEG.
Why use ToolAlto?
ToolAlto provides fast, free online tools for everyday tasks. The image is processed in your browser, with no unnecessary signup.
Frequently asked questions
What image formats can I resize?
The tool accepts image formats supported by your browser. PNG input is kept as PNG; other formats are converted to JPEG for the downloaded result.
How do I resize an image to a specific size?
Choose the image, enter the exact width and height in pixels, then select Resize image. If the dimensions use a different aspect ratio, the result may be distorted.
Will the image keep its aspect ratio?
The tool uses the exact width and height you enter. If those dimensions have a different aspect ratio from the original, the image may appear stretched or squashed.
Can I resize before compressing?
Yes. If an image is much larger than needed, resizing it first can reduce the amount of image data before compression. Then use the Image Compressor if a file-size limit still matters.
Is the image resizer free?
Yes. ToolAlto's Image Resizer is free to use online.