Compress PDF (Free, Private, No Upload)

Large PDFs usually come from scanned pages, embedded photos, oversized images, or document generators that leave unused data behind. This compressor reduces file size in your browser, so the PDF stays on your device while you create a smaller copy for email, upload portals, storage, or messaging.

How the compressor works

The tool uses browser-side PDF processing to optimize the file structure and reduce image-heavy content where possible. Text layers remain searchable, page order is preserved, and the original file is not modified. If a PDF is already highly optimized and a smaller copy cannot be produced, the tool protects you from downloading a larger result.

Best for scans

Photo-based and scanned PDFs usually shrink the most because image data is the largest part of the file.

Preserves text

Digital text remains selectable and searchable, so compression does not turn a normal PDF into a flat image.

Local processing

The work happens in your browser. Sensitive files do not need to be uploaded to a remote compression queue.

Which compression level should you choose?

Start with the recommended ebook setting for general documents. It is the best default for forms, statements, coursework, invoices, and mixed documents with both text and images. Choose screen quality when file size is more important than image detail, such as quick uploads where the recipient only needs to read the text. Choose printer or prepress quality when screenshots, signatures, stamps, diagrams, or product images need to stay crisp.

Step-by-step

Drop a PDF onto the compressor or click the drop zone to select one.
Choose the compression quality that matches how the file will be used.
Click Compress to generate a smaller copy.
Open the result and check important pages before deleting or archiving the original.

What affects the final file size?

A PDF made mostly of selectable text may already be small. In that case, there may be little to remove. A PDF made from phone photos or flatbed scans can often be reduced much more because every page contains large image data. Embedded fonts, duplicated objects, high-resolution backgrounds, and unoptimized exports from design tools can also increase file size.

When not to over-compress

Avoid the strongest compression when a document needs visual inspection. Medical images, legal exhibits, receipts, architectural drawings, certificates, and ID scans may need higher quality. The goal is not the smallest possible file at any cost; it is the smallest file that still preserves the information people need to read.

Related tools: Merge PDF, Split PDF, PDF to Word

FAQ

Is it private?

Yes. Everything runs in your browser; files are not uploaded.

Will text remain searchable?

Yes, compression preserves text layers so you can still search and copy.

How much can it shrink a PDF?

Size reduction depends on images and fonts; scans shrink more than text-only files.

Does compression reduce quality?

Images are resampled to smaller sizes; choose a higher quality level if needed.

Can I compress multiple PDFs?

You can process files one at a time without any limit.