Compress PDF in Browser

The average online PDF compressor asks you to upload a file, waits for a server to process it, and emails or shows you a download link. That trip adds latency, requires a fast internet connection, and — crucially — puts a copy of your document on someone else's infrastructure. For invoices, contracts, NDAs, payslips, lab results and government forms, that is the single biggest privacy hole in a typical workflow.

This tool uses pdf-lib and a custom image re-encoder running inside your browser. The PDF is parsed locally, each embedded image is re-encoded at the quality level you pick, and a new compressed PDF is rebuilt — all without making a single network request that carries your file. You can even disconnect from the internet after the page loads and the tool keeps working.

Choosing a compression level

• Low — best quality, modest 10–25% size reduction. Use for legal documents that must look identical.
• Medium — balanced. 30–50% reduction with images still crisp at 100% zoom.
• High — most aggressive. 50–80% reduction; great for emailing scans, slightly softer images.

When browser-side compression hits its limits

Two situations call for a different approach. First, scanned-only PDFs that are essentially photographs of pages compress best when re-OCR'd and re-saved by Acrobat — browser tools cannot do that. Second, PDFs above ~150 MB can hit the memory limits of mobile browsers; split them first or run the tool on a desktop.

Tips for the smallest possible PDF

• Remove pages you do not need before compressing.
• If a page is just a photo of text, retake it in better light — sharper input compresses better.
• For email, target under 10 MB to clear most inbox limits comfortably.
• Run compression once and inspect the result — repeated compression rarely helps and can blur images.