Compress PDF Online Free

Frequently asked questions

How do I compress a PDF online?

Upload your PDF file. Click compress. The tool repackages the PDF in your browser using pdf-lib. Download the result. Everything runs in your browser; no data is sent to any server.

Are my PDFs sent to a server?

No. Compression is done in your browser. Your PDF never leaves your device.

How much smaller will the file get?

It depends on the original PDF. Repackaging can remove redundant data and sometimes reduce size. PDFs that are already well compressed may not shrink much.

Is quality lost?

This tool repackages the PDF without re-encoding images or text. The content stays the same. Quality is preserved.

Does it work with password-protected PDFs?

Password-protected PDFs must be unlocked first. Open the PDF with the correct password in another app, save without password, then use that copy here.

Does it work on mobile?

Yes. The tool runs in the mobile browser. Upload your PDF, compress, and download. No app install required.

Can I compress multiple PDFs?

This tool compresses one PDF at a time. For multiple files, use it repeatedly or merge them first and then compress the merged file.

What is the difference between compress and merge?

Compress takes one PDF and tries to reduce its file size. Merge takes two or more PDFs and combines them into a single PDF. You can use both: merge first, then compress the result.

Why did my PDF get bigger?

Sometimes repackaging can slightly increase size if the original was very tightly packed. If the tool re-embeds fonts or images differently, the result can be larger.

Is there a file size limit?

There is no fixed limit. Very large PDFs may take longer and use more memory. For typical documents (e.g. under 100 MB), the tool works well.