Image Resizer (Resize by Width & Height)

Resize images online by entering the width and height in pixels or percent. Lock the aspect ratio to scale proportionally, then download as PNG, JPEG, or WebP. Everything runs in your browser — no image is ever uploaded to a server.

What is the Image Resizer?

The image resizer lets you change the width and height of an uploaded image by entering pixel (px) or percent (%) values, all processed directly in your browser. You can keep the aspect ratio locked to scale proportionally, or unlock it to stretch the image to any custom ratio.

The resized image can be saved as PNG, JPEG, or WebP, and you can adjust the quality (compression level) for JPEG and WebP. It's useful for fitting featured images to a blog's recommended dimensions or shrinking a photo to stay under an upload size limit.

How to use it

Choose an image Drag and drop an image into the drop zone, or click it to browse for a file.
Pick a unit Switch between px (exact pixel size) and % (relative to the original image).
Enter width and height Type the target size. With "Lock aspect ratio" on, changing one value automatically updates the other.
Choose an output format Pick PNG, JPEG, or WebP. For JPEG and WebP, use the quality slider to adjust compression.
Download the result Click "Resize & download" to save the image at the size and format you chose.

Tips for getting more out of it

Enlarging (upscaling) an image tends to make it look blurry, so it's best to resize downward whenever possible.
JPEG and WebP use lossy compression — lower quality values shrink the file but reduce image quality too. For images with text or sharp edges (like logos or screenshots), PNG is usually the better choice.
Percent (%) is convenient for relative resizing, like "make this exactly half the original size."
Entering width and height separately with the aspect ratio unlocked will intentionally stretch or squash the image.
To make several images match the same dimensions, enter the same width and height values for each one.

Use cases

Fitting blog or social media dimensions

Match featured images or social posts to a platform's recommended width and height.

Staying under an upload size limit

Shrink the resolution to reduce file size so it fits within a form's upload limit.

Creating thumbnail images

Convert originals to a uniform small size for use as list thumbnails.

Lightening photos for email attachments

Shrink high-resolution photos to a size better suited for email, keeping attachments small.

Glossary

Aspect ratio: The proportion between an image's width and height, such as 16:9 or 4:3. Keeping it locked while resizing preserves the original shape.
px (pixel): The smallest unit that makes up a digital image. A width of "800px" means 800 pixels lined up horizontally.
Lossy compression: A compression method used by formats like JPEG and WebP that sacrifices some image quality to reduce file size. Lower quality values produce smaller files but more visible quality loss.
Upscaling: Enlarging an image beyond its original size. Since new pixels must be interpolated from existing ones, larger upscale ratios tend to look more visibly blurry.

Frequently asked questions

No. Loading, resizing, and downloading all happen entirely in your browser (client-side) — your image data is never sent to any external server.

Yes, but since the process has to interpolate new pixels from the existing ones, larger enlargement ratios tend to look noticeably more blurry. We recommend resizing downward whenever possible.

Use px when you need an exact size, like "exactly 800 pixels wide." Use % when you want a relative change, like "make it half the original size."

Choose PNG if you need transparency or crisp text/graphics. Choose JPEG or WebP for photos where you want a smaller file size — WebP typically achieves better compression than JPEG at similar quality.

Side Note — where the word "pixel" comes from

The word "pixel" is a blend of "picture" and "element," first appearing in image-processing research papers around 1965. A digital image is made up of a grid of tiny colored squares, and each one of those squares is a single pixel.

Resizing an image simply changes the number of squares in that grid. Shrinking averages multiple pixels down into fewer ones, while enlarging interpolates the colors of neighboring pixels to invent new ones. Enlarged images tend to look blurry because that new detail is essentially a best guess rather than real information.

The "standard" image sizes used across the web — a 1200×630px featured image, a square social media avatar, and so on — exist because of how each platform lays out its pages. Checking a platform's recommended size before resizing can save you from unwanted cropping or quality loss after publishing.

Browse all trivia