Upload a JPG, PNG, WebP, or GIF and resize it by exact width and height or by percentage. Lock aspect ratio to avoid stretching, choose an output format, and adjust quality for JPG and WebP. Resizing works on your device—files are not uploaded or stored.

Resizing changes pixel dimensions, which is often more effective than compression alone when a 4000-pixel photo only displays at 800 pixels on a blog. Lock aspect ratio to avoid stretched faces or logos when you change one dimension.

Upsizing a small image cannot invent detail that was never captured. For print, pair resized dimensions with the DPI/PPI Calculator to confirm physical size at your target print resolution.

How to use this tool

1. Choose an image or drag it onto the upload area. 2. Select resize by width and height or by percentage. 3. Enter the target size; keep Lock aspect ratio checked to preserve proportions. 4. Choose an output format and adjust quality for JPG or WebP if shown. 5. Click Resize image, preview the result, and download the resized file.

Worked example

Example: resize a 4000×3000 photo to 1200 px wide with aspect ratio locked—the height scales automatically and you download a smaller JPG ready for web use.

When to use this

Matching social platform dimension requirements.
Downscaling phone photos for web columns or thumbnails.
Preparing retina assets at 2× display width.
Standardizing team headshots to one pixel size.

Common examples

4000×3000 phone photo → 1200×900 for a blog content column at 2× retina width.
LinkedIn headshot 2000×2000 → 800×800 avatar export.
Banner 2400×800 → 1200×400 for faster email newsletter load times.
3000×2000 blog hero → 1600×1067 for faster LCP while keeping 3:2 ratio.
Square logo 1024×1024 → 256×256 favicon source before Favicon Generator.

Common mistakes

Upscaling small images and expecting sharp results.
Ignoring aspect ratio so faces or logos get stretched.
Resizing before crop when composition matters more.
Saving PNG photos that should be JPEG for photo content.

How it works

Load an image, set target dimensions or a percentage scale, optionally lock aspect ratio, choose an output format, then resize on your device with canvas. Files stay on your device.

Limitations

Upscaling cannot recover detail that was not in the original image. Extreme aspect-ratio changes may crop or distort if not constrained.

Privacy and file handling

Your data stays on your device and is not uploaded.

Related Resize Image workflows

Explore focused guides that reuse this resize image with different examples and FAQs.

Related comparisons

Learn how formats and terms differ before you convert or calculate.

HEIC vs JPG

FAQ

Frequently asked questions

Are my images uploaded to a server?

No. Resizing works on your device. Files are not uploaded or stored by Utilnivo.

Which image formats are supported?

You can upload JPG, PNG, WebP, or GIF. Output can stay the same format, or you can export as JPG, PNG, or WebP. Animated GIFs become a single still frame.

What does lock aspect ratio do?

When enabled, changing width automatically updates height (and vice versa) so the image is not stretched.

What is this tool?

Changes image width and height in pixels while keeping aspect ratio optional.

Does this run in the browser?

This tool runs in your browser. Your inputs are not uploaded to our server.

Will quality be affected?

Enlarging images can look soft; shrinking usually preserves acceptable quality.

Which related tools should I use next?

Try Image Compressor, Crop Image, or WebP to JPG.

Part of these workflows

This tool is one step in a longer job. Jump straight to your step or open the full workflow guide.

Page last reviewed: July 6, 2026

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