📦

PDF Compressor

Reduce PDF file size with quality control — entirely in your browser.

📄

Drag a PDF here, or

PDF files only

🔒 Your file never leaves your device. Pages are rendered locally using PDF.js and packed into a new PDF — no server involved.

⚠️ This tool converts each page to an image, then repackages them. Text will not be searchable or copyable in the output. For documents where searchability matters, use a tool like Ghostscript locally.

How to compress a PDF online

Upload your PDF using the button above or by dragging it into the drop zone. Use the Image quality slider to control compression aggressiveness — lower values mean smaller files with slightly softer text and images. The Resolution slider controls the DPI at which each page is rendered; 150 dpi is a good balance for screen viewing, while 96 dpi produces the smallest files and 300 dpi is suitable for print-quality output. Click Compress PDF to process, then download the result.

How does browser-based PDF compression work?

Each page of your PDF is rendered onto a canvas at the selected resolution using PDF.js — the same library that powers Firefox's built-in PDF viewer. Each canvas is then encoded as a compressed JPEG image and packed into a new PDF using jsPDF. The output is a flat image-based PDF, which is typically 50–85% smaller than the original for document-heavy files.

What quality and DPI settings should I use?

For most use cases — emailing a document, uploading to a web form, sharing via WhatsApp — 72% quality at 150 dpi is the right starting point. If the output looks blurry or you need crisp text for presentation, increase quality to 85%+ or DPI to 200. If size is the only priority and the document is mostly text, drop to 55–65% quality at 96 dpi.

Frequently asked questions

Is my PDF uploaded to a server?
No. Everything runs inside your browser tab using PDF.js and jsPDF. Your file is never sent over the network.
Will the text in my PDF still be selectable after compression?
No. The output is an image-based PDF — each page becomes a JPEG image. Text cannot be selected, searched, or copied from the output. This is the tradeoff that makes aggressive compression possible in a browser without a server-side tool like Ghostscript.
How much compression can I expect?
Typically 50–85% size reduction for standard document PDFs. PDFs that already consist mostly of images (scanned documents) will compress less. Very small PDFs (under 200 KB) may not compress significantly.
What is the maximum file size supported?
There is no hard limit. Large PDFs with many pages (50+) may take longer to process and require more browser memory. Processing happens page by page so it is generally stable even for large files.
Will password-protected PDFs work?
Not currently. Password-protected PDFs will fail to load. Remove the password protection first using another tool before compressing.

Looking for other free tools? Try the PDF Merger, Image Compressor, or QR Code Generator.