Compress PDF

In most PDFs, images take up the vast majority of the file size. Scanned documents are essentially one large photo per page, and reports exported from design software often embed high-resolution pictures. Text and vector graphics, by contrast, are very small.

That is why compression focuses on images: re-encoding them at a lower resolution and quality can reduce a file dramatically while keeping it perfectly readable on screen.

Stronger compression gives smaller files but softer images. For documents that will only be read on screen or attached to an email, stronger compression is usually fine. For documents that will be printed, or that contain small print and detailed diagrams, choose a lighter setting and check the result before sending.

This tool rebuilds each page as an image, which means text in the compressed file will no longer be selectable or searchable. Keep your original if you need to copy text from it later.

If a PDF is mostly plain text, it is probably already small and compression may even make it larger. In that case the original is the better file to send. Very long documents may take a while to process on older phones because every page has to be rendered on your device.

Most online converters upload your file to a server, process it there and send it back. all in tool works differently: the processing code is downloaded to your browser and runs on your own device. Your file is read from your disk into memory, transformed, and handed back to you as a download. It is never sent over the network, so there is nothing for us — or anyone else — to store, read or leak.

You can confirm this yourself: once the page has loaded, you can disconnect from the internet and the tool keeps working. This also means speed depends on your device rather than your connection, which is usually much faster for large files.