Make your PDF smaller. Upload a PDF and re-save it in a compact form, then download the smaller file. Everything happens in your browser — your file is never uploaded anywhere.
Compression depends on your PDF's contents: text-heavy PDFs usually shrink well, while PDFs full of photos barely shrink at all. Results vary.
1. Choose a PDF file. 2. Click Compress PDF & Download. 3. Compare the original and new sizes, and save the smaller file.
PDF files can be surprisingly large: a 10-page report with photos can be 20 MB, and many email systems and forms refuse files over 5 or 10 MB. This free PDF compressor makes your PDF smaller by re-saving it in a compact form, with its internal data packed more efficiently. Upload your PDF, click Compress, and download the smaller file. There is no sign-up, no watermark, and your file never leaves your browser — the whole job happens on your own device.
It is important to be honest about what this tool can and cannot do. Compression depends on what is inside your PDF. A text-heavy PDF — a report, a resume, a book — is mostly text and structure, which packs down well, so it can shrink by 20 to 50 percent. A PDF full of large photos barely shrinks at all, because the photos are already compressed inside the file. If your PDF is mostly photos, compress the photos first with our Image Compressor, or split the PDF into smaller parts with our PDF Splitter.
Suppose you have a 10-page report of 2,000 KB (about 2 MB) that is mostly text with a few small charts. Choose the file, click Compress PDF & Download, and the tool re-saves it with object streams, which pack the internal data tightly. The new file might be about 1,400 KB — 30 percent smaller — with the same pages, the same text and the same layout. Download it as compressed.pdf, check that every page looks right, and email the smaller file instead of the original.
Now take a different file: a 5-page PDF of holiday photos, 8,000 KB (about 8 MB) in size. Compress it here, and the new file might be 7,800 KB — only about 2 percent smaller. That is not a failure of the tool: the photos inside the PDF are already JPEG images, which are already compressed, so there is almost nothing left to squeeze. For this kind of file, the better plan is to make the photos smaller first — open each photo in our Image Compressor, save smaller versions, rebuild the PDF with our JPG to PDF Converter, and then compress that. The result will be far smaller than compressing the photo PDF directly.
A PDF file is not just pages: it contains fonts, images, and a lot of internal structure — cross-reference tables, object lists and metadata — that help a reader find each page quickly. When a PDF is created by a scanner or an office program, that structure is often written in a wasteful way, with repeated data and loose packing. This tool rebuilds the file with pdf-lib: it copies every page into a fresh PDF and saves it with object streams turned on, which compresses the internal structure into a tight, packed form. The pages themselves — the text and images you see — are copied unchanged, so the document looks exactly the same, just with a smaller file size.
Check the result before you delete the original. Open the compressed PDF and confirm every page looks right. Expect more from text PDFs. Reports, resumes and books shrink well; photo albums barely shrink. Compress photos first for big savings. If your PDF is mostly photos, shrink the photos with our Image Compressor before you rebuild the PDF. Compress before emailing. Many email systems reject files over 10 or 25 MB, so compress first and check the new size. Try splitting a huge file. If one PDF is still too big, split it into two smaller PDFs with our PDF Splitter and send them separately.
Expecting every PDF to shrink a lot. Photo-heavy PDFs barely shrink, because their images are already compressed. That is normal, not an error. Deleting the original at once. Keep the original until you have checked the compressed file, in case anything looks wrong. Compressing the same file twice. Running the compressed file through the tool again saves almost nothing, because it is already packed. Using a password-protected PDF. Locked PDFs cannot be compressed until the password is removed. Forgetting the email limit. Even after compression, a very large file may still be over the limit — split it or compress its photos first.
Pro Tip: The biggest wins come from text PDFs: a 2 MB report can become 1.4 MB. For photo PDFs, use the Image Compressor on the photos first — that is where the real megabytes are.
Note: Compression results vary with the PDF's contents. Text-heavy PDFs usually shrink well; photo-heavy PDFs may shrink very little, because their images are already compressed.
How do I compress a PDF? Choose a PDF, click Compress PDF & Download, and the tool rebuilds it in a compact form and saves the smaller file to your device.
How much smaller will my PDF get? It depends on the contents. Text-heavy PDFs often shrink by 20 to 50 percent, while photo-heavy PDFs may shrink by only a few percent, because their images are already compressed.
Are my PDFs uploaded anywhere? No. The compression happens entirely in your browser using the pdf-lib library. Your files never leave your device.
Will compression change how my PDF looks? No. The pages, text, images and layout are copied unchanged. Only the internal structure is packed more tightly, so the document looks exactly the same.
Why did my photo PDF barely shrink? Because the photos inside it are already JPEG images, which are already compressed. To make it much smaller, compress the photos first with our Image Compressor, then rebuild the PDF.
Can I compress a password-protected PDF? No. Locked PDFs cannot be opened by the tool. Remove the password first, then compress the file.
Can I compress the same PDF twice? You can, but it will not help much. Once a file is packed tightly, a second pass saves almost nothing.
What if my PDF is still too big to email? Split it into two smaller PDFs with our PDF Splitter, or compress the photos inside it first. Most email systems accept files up to 10 or 25 MB.