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Compress your images online

Processed directly in your browser — no upload to a server.

How to compress your images

Three steps are enough to reduce file size before publishing, sharing or delivery.

1

Add your images

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

2

Web or Archive?

Use the Web or Archive preset, or set the quality and output format yourself.

3

Download the result

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

Why use our image compressor?

Make images lighter before publishing, make email sharing easier, or compress personal photos without a cloud service.

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Local processing

Files are compressed on your device. They are never uploaded to a server.

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Fast presets

The Web preset reduces file size for online use, while Archive preserves as much quality as possible.

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Common formats

Import JPG, PNG, WebP, HEIC, HEIF or AVIF files, then export to WebP, JPG or AVIF.

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Batch processing

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

Frequently asked questions

How do I compress an image with Constelly? expand_more

Add your images to the tool, choose a compression mode, then start processing. Review the result before downloading each image or the whole batch.

Are my images sent to a server? expand_more

No. Compression 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. Compressed images can be downloaded as WebP, JPG or AVIF.

Can I compress multiple images at once? expand_more

Yes. Add multiple files, use the same settings for the batch, and start compression. You can download images one by one or get the entire batch.

What is the difference between Web, Archive and Manual presets? expand_more

Web reduces file size for online use. Archive keeps a result closer to the original. Manual lets you choose the format and quality level.

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

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

Can I remove device information? expand_more

Yes. Remove file metadata such as capture date, GPS location or camera details before publishing or sharing an image.

Why can a file sometimes become larger after compression? expand_more

This can happen when the original image is already highly optimized, or the selected format is not the best fit. Try another format or a lower quality level.

Which output format should I choose? expand_more

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 compress 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 compression 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.

When should you compress an image?

Reducing a photo’s file size is useful more often than you might think.

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For a faster website

Smaller images make a website load quickly, especially on mobile. That is good for visitors and search visibility.

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For email sharing

Email attachments are often capped at 20 or 25 MB. Compress 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

Smaller files use less space on your disk, cloud storage or memory card.

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Your images never leave your computer

Most compression 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
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person_off No sign-up required

Can you compress an image without damaging it?

Yes. Compression does not have to mean lower quality. The tool optimizes how an image is stored and removes data that does not affect display. Choose the level: light compression keeps quality close to the original, while stronger compression reduces file size further for a result that still looks great on screen.

Web or Archive: which should you choose?

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Web preset

Reduce image size as much as possible for the web, email or social media. Ideal when file size matters more than the finest detail.

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Archive preset

Preserve the best possible quality while reducing file size. Best for keeping photos or editing them later.