Image Resizer

About the Image Resizer

The Image Resizer changes the width and height of a photo or graphic to exactly the size you need. Set new dimensions in pixels or scale by a percentage, keep the aspect ratio locked so nothing looks stretched, choose the output format and quality, and download the result. The preview shows the new dimensions, file size and how much it changed before you save.

It solves everyday problems: a job portal that demands a 600 × 600 photo, a marketplace that wants 1000-pixel product images, a blog theme with a fixed column width, or a 4000-pixel phone photo that is far too big to email. Resizing happens in your browser on your own device, so private photos and scanned documents are never uploaded.

What does resizing an image mean?

A digital image is a grid of tiny coloured squares called pixels. Its dimensions, such as 4032 × 3024, are the number of pixels across and down. Resizing creates a new grid with a different number of pixels and works out the colour of each new pixel from the original, a process called resampling.

The aspect ratio is the relationship between width and height, such as 4:3 for many phone photos or 16:9 for video. If you change width and height by different proportions, the image is stretched or squashed. To change the shape without distortion, you crop first and then resize.

Making an image smaller (downscaling) removes pixels and usually gives a much smaller file with no visible loss at the new size. Making it bigger (upscaling) cannot add real detail: the software only spreads existing pixels further apart, so enlarged images look softer. Resizing is different from compression, which keeps the dimensions but stores the pixels more efficiently.

How to use the Image Resizer

1. Click the drop area, drag an image onto it, or paste one with Ctrl+V. The original dimensions, size and format are shown.
2. Choose By pixels to enter an exact width and height, or By percentage to scale the whole image, for example 50%.
3. In pixel mode, keep Keep aspect ratio ticked; changing the width updates the height automatically, and vice versa. Untick it only when you need an exact shape and have cropped first.
4. Choose the output Format: same as original, JPG, PNG or WebP, and adjust Quality for JPG and WebP (default 90%).
5. Check the preview, the new dimensions and the size change, then click Download.

Choose another image loads the next file with the same percentage, format and quality (the pixel fields reset to the new image’s size), and Reset starts again. The preview updates automatically each time you change a setting.

Key features and benefits

• Pixels or percentage. Exact dimensions for forms and websites, or quick proportional scaling from 1% to 1000%
• Aspect ratio lock. Width and height stay in proportion so photos never look stretched
• Sharper downscaling. Large reductions are done in several halving steps, which reduces jagged edges compared with one big step
• Format conversion. Save as JPG, PNG or WebP while you resize, with a quality slider for lossy formats
• Before-and-after details. New dimensions, new file size and the percentage change are shown before you download
• Private. Images are processed with the browser’s Canvas API on your device and never uploaded

Practical examples

Photo for a blog post

A phone photo is 4032 × 3024 pixels and 3.8 MB. At 25% it becomes 1008 × 756 pixels, a good size for an article column, and the file is usually a fraction of the original. With the ratio locked, typing a width of 1200 instead gives 1200 × 900.

Square photo for an application form

A portal requires exactly 600 × 600 pixels. First crop the photo to a square with the Image Cropper, then enter 600 × 600 here. If you resize a rectangular photo to 600 × 600 with the lock off, the face will look stretched.

Product images for an online shop

A marketplace recommends 1000 × 1000 pixels. Crop each product photo square, resize to 1000 × 1000, and save as JPG at 85% for a small, sharp file. Using the same size for every product keeps your listing grid neat.

Transparent logo

A 2000 × 800 PNG logo is resized to 25% (500 × 200) for an email signature. Keep the format as PNG or WebP to preserve transparency. Saving as JPG fills transparent areas with white.

Common use cases

• Job seekers and students meet exact photo and signature dimensions on application portals.
• Bloggers and website owners resize images to their display width so pages load faster.
• Online sellers make all product photos the same size for marketplace listings.
• Designers and marketers prepare banners, thumbnails and social media images.
• Everyone shrinks large phone photos before emailing or sharing them.

Accuracy, limitations and privacy

Resizing uses the browser’s canvas with high-quality smoothing, and large reductions are done in halving steps for cleaner results. Output quality and WebP support depend on your browser: Chrome, Edge and Firefox can save WebP, while some older browsers can only save JPG or PNG, in which case the tool tells you it saved PNG instead. Re-encoding removes metadata such as camera details and GPS location.

All processing happens on your device. Nothing is uploaded or stored, and the image is discarded when you close the page.

• Each side can be at most 12,000 pixels.
• Upscaling cannot create real detail; enlarged images look softer.
• Animated GIFs are saved as a single still frame, and HEIC photos must be converted to JPG first.
• Colour profiles are not preserved.

Tips and best practices

• Resize to the largest size the image will actually be displayed at; for full-width website images that is often 1200–1600 pixels wide.
• Crop first, then resize, when you need a particular shape such as a square.
• After resizing, run the image through the Image Compressor if you need an even smaller file.
• Keep the original file: resizing down and then up again loses detail.
• Check the form’s requirements for both pixels and file size in KB; you may need both tools.

Related tools and next steps

To shrink the file further after resizing, use the Image Compressor. Crop to an exact shape with the Image Cropper, check dimensions with the Image Dimensions Checker, and rotate or flip photos with the Image Rotator. To make website icons from a logo, try the Favicon Generator.