Are online image compressors safe?

Server-side. Your file is transmitted to a server, processed there and returned. A copy exists on infrastructure you cannot inspect, for a period you are taking on trust, accessible to whoever operates it and to anyone who obtains the URL.

Client-side. The page loads code that runs in your browser, and the file is read from disk into the tab's memory, processed, and written back. No copy exists anywhere else because none was ever transmitted.

Neither is automatically dishonest. Server-side processing has genuine advantages — heavier codecs, no device memory limits, formats a browser cannot handle. But it is a different relationship, and it should be a deliberate choice rather than something you discover afterwards.

You do not have to take anyone's word for it. Two checks, neither requiring technical skill:

The offline test. Load the page, then disconnect from the internet — Airplane Mode, or unplug the network. Now compress an image. If it works, the processing is happening on your device. If it fails or hangs, your file was going somewhere.

The network panel. Open your browser's developer tools, go to the Network tab, and compress an image. A server-side tool shows a large upload request; a client-side one shows nothing leaving at all.

These tests work on any tool, including this one.

For a photograph of a sunset, very little. The concern is proportional to what the image contains.

• Identity documents. Passport photographs, driving licences, ID cards — the highest-value target there is.
• Signatures. Frequently uploaded to compressors for exam and government forms.
• Financial and medical documents. Photographed statements, prescriptions, test results.
• Photographs of children. Especially with location metadata attached.
• Anything commercially confidential. Unreleased products, internal screenshots, contracts.
• Any photograph taken at home, where GPS coordinates identify where you live.

Notice how much of that list overlaps with the reasons people search for a compressor in the first place — form uploads with strict size limits are exactly where identity documents show up.

Independent of where processing happens: your photographs carry EXIF metadata including camera model, timestamps and, if location services were on, coordinates accurate to a few metres.

If a tool preserves metadata, those coordinates travel with every copy — to the service, and to wherever you upload the result. If it strips metadata, they are removed as a side effect of re-encoding.

This matters even when the tool itself is trustworthy, because the file usually goes somewhere else afterwards.

1. Does the file leave my device? Can I verify that rather than being told?
2. If it is uploaded, how long is it retained, and is that a specific period or a vague reassurance?
3. Is the connection encrypted, and are the resulting download links unguessable?
4. Does the privacy policy name subprocessors, or does it stop at "trusted partners"?
5. Is metadata stripped, and can I choose?
6. Who operates this, and is there a real entity behind it?

A tool that cannot answer the first question clearly is not one to hand an identity document to.

Every tool here runs in your browser. There is no upload endpoint in the compression path — your file is read from your own disk into the memory of the tab, re-encoded there, and offered back as a download.

That is a claim, and you should test it rather than believe it. Load any tool page, turn off your network connection, and compress an image. It will still work.

What we do collect is ordinary: standard server logs for the pages themselves, and contact form messages if you send one. Both are described in the privacy policy.