Compress PDF Online Free | Smaller Files

How to Compress a PDF Online

Choose your PDF. Upload one document, up to 25 MB. Use an unencrypted copy that opens normally in a PDF reader.
Click Compress PDF. The tool rewrites compatible parts of the file and removes wasted space to reduce the PDF file size, without lowering image quality.
Check before you share. Download the result and compare the size. Then open a few text-heavy and image-heavy pages, and keep the compressed copy only if it’s smaller and looks right.

Lossless compression works best when a PDF stores its content inefficiently. If your software already optimized the file, it may shrink only a little, or not at all. In that case you’ll get your original back unchanged.

A PDF document being prepared for a smaller optimized download

Benefits of Compressing a PDF

Fits email attachment limits

Reduce your PDF file size so it’s less likely to hit the attachment limit in Gmail, Outlook, or other email services, and sends faster on a mobile connection.

Faster PDF downloads

Trim unnecessary bytes so reports, forms, and brochures open quicker for your website visitors.

Easier portal uploads

Help a CV, assignment, or application document fit a stated upload limit.

Compress PDF without losing quality

Lossless optimization doesn’t downsample photos or turn readable text into a lower-resolution picture.

Your original stays safe

You download a separate smaller PDF, so the source file on your device isn’t overwritten.

Free on any device

Compress a PDF online from a phone, tablet, laptop, or desktop, with no signup.

What Our PDF Compressor Can and Can’t Do

This tool compresses PDFs with lossless optimization. It cleans up how the file is stored without touching how it looks, so your text stays selectable and your links, page order, and page sizes stay exactly as they were. That makes it a good choice when you want to compress a PDF without losing quality. Your original file isn’t overwritten, because the download is a separate copy.

Lossless compression has a clear limit. A large scanned PDF gets most of its size from high-resolution photos of each page, and shrinking those usually means downsampling the images or using lossy compression, which this tool doesn’t do. If you need the smallest possible file, you’ll want a different approach for scans. Embedded video, unusual fonts, encryption, a damaged file, and complex interactive content can also limit how much the PDF file size can be reduced.

Before you delete the original: Compare the file sizes, zoom in on small text and diagrams, and test any important links or form fields. Then check that the PDF opens in the software your recipient uses. For records, legal documents, and print masters, always keep the original, even when the smaller copy looks perfect.

Who Benefits From Compressing a PDF?

Anyone who sends, uploads, or publishes PDFs can benefit from a smaller file, as long as it still looks right.

Remote and Mobile Workers

Reduce the PDF file size so documents upload and send faster on a slow or mobile connection.

Applicants and Students

Bring a CV, portfolio, or assignment closer to a portal’s upload limit without lowering image quality.

Website Publishers

Lower the download size of reports, brochures, and forms, so they open faster for your visitors.

Administrative Teams

Make email-friendly copies of documents for sending, while keeping the original high-quality PDF in your records.

Frequently Asked Questions

Yes. You can compress PDF files online for free, and you don’t need to sign up. Upload your file, click Compress PDF, and download the result.

No. This tool uses lossless compression, so you can compress a PDF without losing quality. Your text and images aren’t degraded, and photos aren’t downsampled.

If the tool can’t reduce the file size, it returns your original PDF unchanged, so the result is never bigger than what you uploaded. This often happens with files that are already optimized, and with scans.

You can upload one PDF of up to 25 MB for each compression request.

You can upload a valid scanned PDF, but the savings are often limited, because a scan is mostly large images of each page. Shrinking those usually needs lower image quality, which this lossless tool doesn’t apply.

No. Your original file stays as it is, and the tool creates a separate, smaller copy for you to download. Keep the original anyway, especially for records, legal documents, and print files.

Upload your PDF, compress it, and compare the size. If it’s still too large for your email provider’s attachment limit, try removing pages you don’t need with our Delete PDF Pages tool, or splitting the file with Split PDF.

No. This tool doesn’t let you set a target size, and lossless compression can’t promise one. For a smaller file, try compressing the images first with our Compress Image tool, removing pages, or splitting the document.