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Compress PDF
Reduce PDF file size in your browser. The tool re-saves your PDF in a tighter form and strips out extra file details — then shows you the before and after size, so you can see exactly what changed.
Example: a 5-page text test PDF of 2,227 bytes re-saved with object streams stayed at 2,227 bytes — text PDFs are often already packed tight, so the saving is small. The tool shows your real before and after size.
Your compressed PDFReady to download
Pick a PDF and press Compress PDF. The tool re-saves it in a tighter form and shows the before and after size here.
How to compress a PDF
- Click the box above, or drag your PDF onto it.
- Leave "remove title, author and other details" ticked — it takes out a small block of extra data.
- Press Compress PDF. The tool re-saves the file with object streams, in your browser.
- Download the result and compare the sizes in the panel on the right.
Worked example — what actually shrinks, and what does not
We tested the tool on a 5-page text-only PDF of 2,227 bytes. After re-saving with object streams, it was still 2,227 bytes — a 0% saving. That is normal for text PDFs made by modern tools: their text is already packed tight, so there is nothing left to squeeze. The saving comes from PDFs saved without that packing — older files, files saved by apps that skip it, and files carrying extra details — where the same re-save can cut a real share of the size. This page never hides the result: it prints the before and after size for your file, so you can judge for yourself. If your file is mostly photos, shrinking the images is what helps — see the guide on how to compress a PDF for the steps that matter most.
Frequently asked questions
How can I compress a PDF for free?
Open this page, add your PDF, and press Compress PDF. The tool re-saves it in a tighter form and shows the before and after size. There is no account, no email, and no fee.
How much smaller will my PDF get?
It depends on the file. Text-only PDFs made by modern tools are often already packed tight, so the saving can be small — our 5-page test file went from 2,227 bytes to 2,227 bytes. Files saved without packing, or carrying extra details, shrink more.
Does compressing a PDF lower the quality?
No. This tool does not touch the text or the images in your pages — it only re-packs the file itself. The pages look exactly the same.
Is my PDF uploaded anywhere?
No. The compression runs fully in your browser with the pdf-lib library, which is stored on this site. Your file never travels over the internet.
My PDF is mostly photos and still too big. What now?
Re-saving alone will not shrink photos much. Make the photos smaller first — our image compressor can shrink a photo — then rebuild the PDF, or print the PDF to a new PDF at a lower quality in your PDF reader.
Your files never leave your device. This tool runs fully in your browser. Your files are not uploaded to any server, not stored anywhere, and not seen by anyone else. Close the tab and they are gone.
Sources and method. pdf-lib 1.17.1 (vendored on this site). Compress tested in Node: a 5-page, 2,227-byte text PDF re-saved with object streams measured 2,227 bytes — 0% change, as the copy above says.