Resize your
images online

Use a percentage or exact pixel dimensions, directly in your browser.

How to resize your images

Three steps are enough to adjust your files before publishing, sharing or delivery.

1

Add your images

Drag and drop your files, or select them from your device.

2

Percentage or pixels?

Scale by percentage, or set an exact width and height in pixels.

3

Download the result

Download each image separately or the entire batch in a ZIP file.

Why use our image resizing tool?

Adjust images before publishing, meet an exact template, or reduce photo dimensions without using a cloud service.

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Local processing

Files are resized on your device. They are not sent to a server.

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Percentage or pixels

Scale by percentage, or set an exact width and height in pixels.

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Common formats

Import JPG, PNG, WebP, HEIC, HEIF or AVIF files, keep the original format, or convert as you resize.

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Batch processing

Add several images, resize them in one go, and download a ZIP archive.

Frequently asked questions

How do I resize an image with Constelly? expand_more

Add your images to the tool, choose a mode (percentage or pixels) and the desired dimensions, then start processing. Review the result before downloading each image or the whole batch.

Are my images sent to a server? expand_more

No. Resizing happens directly in your browser. Your images stay on your device throughout the process.

Which file formats are supported? expand_more

You can import the most common image formats, including iPhone photos. The original format is kept by default, but you can also export to WebP, JPG or AVIF.

Can I resize multiple images at once? expand_more

Yes. Add several files, use the same settings for the batch, and start processing. Download images one by one or get the complete batch.

What is the difference between Percentage and Pixels mode? expand_more

Percentage mode scales every image identically without distorting it. Pixels mode lets you set an exact width and height, with the option to preserve proportions or stretch the image to those dimensions.

What is the before-and-after comparison for? expand_more

It lets you check the result visually before downloading. Compare the original and resized images to decide whether the setting works for you.

Is EXIF metadata preserved? expand_more

No. Metadata is removed automatically, including capture date, GPS location and device details. This is useful before publishing or sharing an image.

What happens if I request a size larger than the original? expand_more

If "Allow upscaling" is checked, the image is enlarged, which can reduce sharpness beyond its original resolution. If it is unchecked, the size stays capped at the original resolution.

Which output format should I choose? expand_more

"Default" keeps each image's original format and is the simplest choice. WebP is often a good choice for the web. JPG remains the most compatible format. AVIF can create smaller files, but check that it is supported where you plan to use the image.

Do I need an account? expand_more

No. You can resize images without signing up. Pro access is only for regular use or larger batches.

Does the tool work offline? expand_more

Yes, once the page has loaded. You need internet to open the tool, but resizing itself can happen without sending files online.

What file size is recommended? expand_more

For smooth processing, use reasonably sized files. Very large images may take longer because processing depends on your device.

Is image resizing free?expand_more

Yes, image resizing is free and requires no sign-up. To process large volumes or use it regularly, switch to Pro.

When should you resize an image?

Adjusting a photo's dimensions is useful more often than you might think.

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To meet an exact template

A banner, product thumbnail or avatar often needs exact pixel dimensions. Pixels mode handles that in one pass.

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For email sharing

Email attachments are often capped at 20 or 25 MB. Reduce your photos to send more without hitting the limit.

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For galleries and portfolios

Send lightweight previews to clients or publish a portfolio that loads instantly without sacrificing image quality.

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To save space

Lower-resolution images use less space on your disk, cloud storage or memory card.

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Your images never leave your computer

Most resizing tools upload photos to their servers. Not here. Everything happens in your browser: your images stay with you. It is faster, and photos of clients, projects or memories are never transferred or stored elsewhere.

cloud_off Nothing is uploaded
lock Nothing is stored
person_off No sign-up required

Can you resize a photo without distorting it?

Yes. Percentage mode scales each image equally on both axes, so distortion is impossible. In Pixels mode, with "Keep proportions" checked, the requested width and height define a box in which the image is reduced without stretching. Uncheck it to stretch the image to the exact dimensions, which is useful for a fixed template but may distort a different original ratio.

Percentage or Pixels: which should you choose?

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Percentage mode

Scales every image in the batch equally, whatever its original ratio. Ideal for reducing a set of photos without worrying about exact dimensions.

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Pixels mode

Sets an exact width and height in pixels. Best when a precise template is required, such as a banner, thumbnail or avatar.