Compress PDF
Reduce PDF file size while maintaining quality
Drop a PDF file here or click to browse
Files processed in your browser — never uploaded
Lossless Mode
Optimizes PDF structure without reducing image quality. Best for documents with text.
Custom Compression
Fine-tune compression with a slider for precise control over file size.
Target Size
Enter your desired file size and we'll calculate the optimal compression settings.
How to Compress a PDF Without Uploading It
Most PDF compression tools require you to upload your file to a remote server. PDFb2 works differently. When you compress a PDF here, the entire process runs inside your browser using JavaScript. Your file is read locally, compressed locally, and saved locally. No data is transmitted over the internet, and no copy of your document exists on any server at any point.
This matters for anyone working with contracts, tax returns, medical records, legal filings, or any document containing sensitive information. Uploading these files to a third-party service creates risk — even if the provider promises to delete files after processing, backups and caches may retain copies.
Lossless vs. Lossy PDF Compression
PDFb2 offers two approaches. Lossless compression optimizes the internal structure of your PDF — removing duplicate objects, cleaning up unused data, and streamlining embedded resources — without touching image quality. This typically reduces file size by 5-15% while keeping the document identical to the original.
Lossy compression goes further by re-rendering pages at a lower resolution. This can reduce file size by 50-90%, which is useful for email attachments or web uploads where smaller files matter more than maximum fidelity. The Custom Compression slider and Target Size mode give you precise control over the balance between quality and file size.
Who Uses Client-Side PDF Compression
Legal professionals use it to shrink court filings without risking privileged content. Financial advisors compress client statements before archiving. Healthcare workers reduce the size of scanned patient records while maintaining HIPAA compliance. HR teams compress employee documents for internal systems. Freelancers and small business owners use it to meet email attachment size limits without paying for software subscriptions. If you need a smaller PDF and you care about where your file goes, client-side compression is the straightforward answer.