Free PDF compressor
Reduce PDF Size Online
Make a PDF smaller for email, forms, and sharing—right in your browser.
- Files stay on your device
- Your original stays unchanged
- No signup required
- PDF files up to 100MB
Your PDF
Compress locally
Drop your PDF here
or choose one file from your device
PDF only · Maximum 100MBThree simple steps
How to Reduce PDF File Size
You can reduce the size of an existing PDF without recreating the document.
Everyday uploads
Make a PDF Smaller for Uploading
Email services, job applications, government forms, and other websites often limit attachment size. Start with Balanced for a practical mix of clarity and compression.
If your PDF is still over the destination's limit, try Smallest Size and check the downloaded file before submitting it. The exact result depends on what is inside your PDF.
Reduce a PDF nowA clear tradeoff
Reduce PDF Size Without Losing Quality
Compression can change image quality. Choose the lightest level that gets your file where it needs to go.
Comparison guide only — choose a level in the compressor above.
| Compression level | Best for | Tradeoff |
|---|---|---|
| 01High Quality | Detailed images, charts, and documents you plan to inspect closely. | Prioritizes image clarity, so size reduction is usually more modest. |
| 02BalancedRecommended default | Ordinary sharing, email attachments, forms, and online uploads. | A practical balance between readable output and a smaller file. |
| 03Smallest Size | Strict upload limits when the other levels still produce a large PDF. | Prioritizes a smaller file; fine image details may appear less sharp. |
See measured results for all three levels across eight test PDFs
Image-heavy documents
How to Compress a Scanned PDF
A scanned PDF often stores each page as a high-resolution image, so image downsampling and re-encoding can reduce its size more than a text-only document.
Start with Balanced and inspect small text, stamps, signatures, and thin lines in the output. Strong compression can make those details less clear.
Useful answers
Frequently Asked Questions
How do I make a PDF file smaller so I can upload it?
Use Balanced compression first, then compare the output with the upload limit shown by the destination website. If the file is still too large, run the original PDF again with Smallest Size. Results vary because image-heavy and scanned PDFs behave differently from files that mainly contain text.
What should I do if my PDF is still too large?
Try Smallest Size and inspect the downloaded copy carefully. If that is still too large, the document may already be optimized or may contain content that cannot be reduced much without a larger quality change. This tool will not present a larger output as a successful compression. See the measured reasons a PDF will not compress.
Can I reduce PDF size without losing quality?
You can often make a PDF smaller while keeping it clear enough for its intended use, but compression is not guaranteed to be lossless. High Quality makes the smallest visual compromise, Balanced suits everyday sharing, and Smallest Size trades more image detail for a lower file size.
Can I compress a PDF to 1MB or 300KB?
You can try to reach 1MB or 300KB, but this version does not support an exact target size and cannot guarantee either result. Choose a compression level, check the output size, and use a stronger level if necessary. The achievable size depends on the PDF’s pages, images, fonts, and existing optimization.
Does this tool work with scanned PDFs?
Yes, many scanned PDFs can be reduced because their pages are stored as large images. Balanced is a sensible first choice. Review small text, stamps, signatures, and fine lines in the downloaded PDF, since stronger image compression may make those details less sharp.
Are my PDF files uploaded to a server?
No. The selected PDF is passed from the page to a dedicated browser worker and processed locally on your device. The app does not send the PDF bytes through a form, analytics service, or compression API. Resetting the tool or closing the page removes the in-memory result and its temporary download URL. Read the privacy details.
Evidence and methodology
Sources Behind This PDF Compressor
Product claims are checked against the public implementation and primary documentation. Last reviewed .
Ghostscript explains that pdfwrite creates “a new PDF file.” That is why this site tells you to keep the original and inspect every compressed result.
- Ghostscript: High Level Devices and pdfwrite
Primary documentation for pdfwrite behavior, output caveats, image downsampling, and the screen, ebook, and printer PDFSETTINGS presets.
- Reduce PDF Size source code
The public implementation, worker path, build files, tests, license, and change history used to verify the product claims on this page.
- Firebase: Get started with Google Analytics for Web
Primary documentation for the optional usage measurement disclosed on the Privacy page.