If the tool does not start

Your browser does the compression. It needs capabilities that older browser versions may not provide.

Things to try

Check that JavaScript is enabled for this site.
Update to the newest browser version available for your device. If that is not possible, try another device you trust.
Close tabs you do not need. A large PDF can run out of memory even when it is within the file-size and page-count limits.
Check that the original file opens correctly and that the PDF is not password protected.

Support for browsers more than 10 years old has not been verified. PDF processing needs more browser capabilities than an ordinary image. If local processing fails, your document is not sent to a server instead.

An older computer is not the same as an older browser

A device’s age alone does not determine whether compression works. Browser version, available memory and operating-system updates also matter. Long PDFs can take considerably more time than a single image.

You can read the guides and privacy information without running the compression tool.

Back to your document