Image Tools

Image Resizer

Resize any image to a custom width and height, with an option to keep the aspect ratio. Processing happens locally in your browser.

Click to choose an image

Need more than one step? Batch-process, convert and ZIP your images in Image Studio — all in your browser.

How to resize an image

Choose a JPG, PNG or WebP image.
Type the new width or height in pixels. With Keep aspect ratio ticked, the other side updates automatically so nothing gets stretched.
Untick the lock only when you need an exact width and height of a different shape — the picture will be squashed or stretched to fit.
Resize and download. PNGs stay PNG; other formats are saved as high-quality JPG.

The aspect-ratio formula

Keeping proportions is simple arithmetic: new height = new width × original height ÷ original width. A 4032 × 3024 phone photo resized to 1600 pixels wide becomes 1600 × 3024 ÷ 4032 = 1200 pixels tall. The tool does this for you whenever the lock is on, rounding to the nearest whole pixel.

Target width	Resulting size	Pixels kept	Typical use
3024	3024 × 2268	56%	High-quality archive copy
2048	2048 × 1536	26%	Large screens, cloud albums
1600	1600 × 1200	16%	Blog posts and websites
1200	1200 × 900	8.9%	Email and chat
800	800 × 600	3.9%	Thumbnails and forms

Common target widths for a 4:3 photo such as 4032 × 3024, with the aspect ratio locked.

Why resizing shrinks files so much

File size follows pixel count, and pixel count falls with the square of the scale. Halve both the width and the height and you keep only a quarter of the pixels, so the file typically drops to around a quarter of its size at the same quality. That's a far bigger saving than any quality slider can deliver without visible damage, which is why resizing to the size you actually need is the first step of good image optimisation.

Enlarging works the other way, and not in your favour: new pixels have to be invented by blending neighbouring ones, so an upscaled photo looks soft. Scaling up by 10–20% is usually unnoticeable; doubling a small image is not.

Picking a size for where the image will appear

Websites: about twice the width of the space the image fills, to stay sharp on high-density screens — 1400–1600 pixels for a typical blog column, 2400–2560 for full-width banners.
Email newsletters: most templates are about 600 pixels wide, so 1200 pixels covers high-density screens.
Presentations: 1920 × 1080 matches a standard 16:9 slide at full HD.
Printing: divide the pixels by 300 to get the sharp print size in inches — 1800 × 1200 pixels prints well at 6 × 4 inches.

Resizing without losing sharpness

Resize from the original every time. Shrinking an image that was already resized and compressed stacks one loss on top of another.
Go straight to the final size in one step; shrinking gradually over several passes gains nothing.
Photos with fine detail such as text, fabric or foliage can look slightly soft after a big reduction — viewing them at their final display size is the fair test.
Screenshots and graphics are best kept as PNG when resized, which this tool does automatically, so edges and lettering stay crisp.

Frequently asked questions

Will resizing reduce image quality?

Making an image smaller keeps it crisp. Enlarging beyond the original dimensions can look soft, since there is no extra detail to add.

What's the difference between resizing and cropping?

Resizing scales the whole picture up or down and keeps everything in the frame. Cropping cuts away part of the picture to change its shape or remove distractions. When a form demands an exact shape, crop first, then resize to the exact pixel size.

Can I resize to exact dimensions like 1080 × 1080 without distortion?

Only if the original already has that shape. For a different shape, crop instead of stretching — the Resize Image for Instagram tool crops to exact sizes such as 1080 × 1080 and keeps the centre of the photo.

Does resizing change the file format?

PNG files stay PNG, so any transparency survives. JPG, WebP and other formats are saved as JPG at 92% quality, which is visually indistinguishable for photos.