Compress a PDF

Compress a PDF is a free tool that runs entirely in your browser, with no data ever sent to a server. Shrink a document by recompressing its internal JPEG images.

What this tool touches, and what it leaves alone

Most heavy PDFs owe their size to the photographs they contain, almost always stored in JPEG format inside the file. This tool finds those images, recompresses them at a lower quality, and keeps the result only if it's genuinely lighter than the original.

Images in a CMYK color space, vector graphics, text, and black-and-white scanned documents (often stored in a compressed fax format) are left untouched : decoding them correctly would require much heavier machinery than a simple pass through the browser, with a risk of damaged colors we'd rather avoid.

Choosing the quality

Between 50 and 70%, the loss is usually hard to spot on screen, for a substantial size reduction. Below 40%, high-contrast areas (scanned text, thin lines) start to show artifacts.

What this tool does not do

This tool does not support password-protected PDFs. It does not preserve bookmarks or form fields, and compression only affects images already in JPEG format inside the document.

Frequently asked questions

Why doesn't my PDF shrink?

Either it holds no JPEG image in a supported color space, or its images are already compressed harder than the quality chosen here : in that case, the tool keeps the original rather than produce a heavier file.

Does the text stay sharp after compression?

Yes : a PDF's text is almost always vector text, not an image. Only photographs are affected by the quality setting.

Are my files sent to a server?

No : the processing happens entirely in your browser, on your device. No file is ever transmitted to a server.