Does compression reduce PDF image quality?

Our compression uses lossy optimization for images, which typically reduces file size by 30-70% with minimal visible quality loss. For scanned documents, you'll see the most compression (50-80% reduction). For PDFs with text and vector graphics, compression is lossless and maintains perfect quality. You can preview the compressed file before downloading to verify quality.

Can I compress password-protected PDFs?

No, password-protected PDFs must be unlocked first before compression. Use our PDF Unlock tool to remove the password, then compress the unlocked PDF. This is a security feature to prevent unauthorized access during processing.

What's the maximum file size I can compress?

The practical limit is your browser's available memory, typically 50-100MB depending on your device. For best performance, we recommend files under 50MB. Files larger than 100MB may cause browser crashes. For very large files, use desktop software like Adobe Acrobat.

How much can I compress my PDF?

Compression rates vary by content type: Scanned documents (50-80% reduction), PDFs with images (30-70% reduction), Text-only PDFs (10-30% reduction). The actual compression depends on image quality, embedded fonts, and document structure. Our tool shows estimated compression before processing.

Will the compressed PDF work in all PDF readers?

Yes, compressed PDFs maintain full compatibility with all PDF readers (Adobe Reader, Chrome, Firefox, etc.). We preserve all PDF features including bookmarks, links, and form fields. The compression only optimizes images and removes unnecessary metadata.

Is it safe to compress sensitive or confidential PDFs?

Yes. PureXio processes your PDF entirely in your browser. Your file never leaves your device and is never uploaded to any server. This makes it one of the safest ways to compress confidential documents, contracts, medical records, or financial statements online.

What is the difference between the compression levels?

Fast compression applies light optimization, resulting in smaller file size reductions (10-30%) but preserving near-original quality. Medium compression balances size and quality (30-60% reduction). Maximum compression aggressively reduces file size (60-90% reduction) but may slightly affect image quality within the PDF.

Can I compress multiple PDFs at once?

Currently, the tool processes one PDF at a time for maximum reliability. However, you can compress files sequentially — each compression takes only a few seconds. Batch compression may be added in a future update.

PDF Compressor - Reduce Size by 90% Free

When to Use This Tool

Use this when:

Your PDF exceeds email attachment limits (25MB) and needs to be under 10MB
You need to compress scanned documents (5MB → 800KB) for email sharing
You're preparing presentations for file sharing and want to reduce size without quality loss
You have multiple invoices (3-5MB each) that need compression for archiving
You need to compress a 50MB presentation to under 10MB for upload to a form
You're sending PDFs via email and need to meet size restrictions
You want to reduce PDF file size for faster web uploads or downloads

Don't use this if:

You need to compress PDFs larger than 100MB (use desktop software like Adobe Acrobat)
Your PDF contains complex vector graphics requiring specialized compression tools
You need batch processing of 50+ files (consider desktop software or API)
You require lossless compression with zero quality reduction (use specialized PDF tools)
You need to compress password-protected PDFs (remove password first, then compress)

What is a PDF Compressor?

A PDF compressor is an online tool that reduces the file size of PDF documents while maintaining acceptable visual quality. Our browser-based compressor processes everything locally on your device — no file uploads, no cloud servers, no data collection.

PDF compression is essential when you need to meet email attachment limits (often 10–25 MB), share files faster over slow connections, or save storage space on devices and cloud drives. Whether you're working with scanned documents, image-heavy presentations, or invoice archives, compression can typically reduce file sizes by 30–90% depending on the content.

This tool is ideal for office workers sharing reports by email, students submitting assignments to upload portals, freelancers sending proofs to clients, and anyone who handles PDF files regularly. Unlike desktop software like Adobe Acrobat (which requires a paid subscription) or other online compressors that upload your files to remote servers, PureXio processes everything in your browser using WebAssembly technology.

No installation, no account creation, no file size limits enforced by a server — just drag, drop, and download your compressed PDF in seconds. Your sensitive documents stay completely private throughout the entire process.

Best for: compressing PDFs up to 100 MB without uploading to any server. Typical size reduction: 30–90%. 100% browser-based, fully private.

How to Compress PDF

Drop your PDF file (up to 100MB) or click to browse and select your file

Choose compression level (Fast, Medium, or Maximum) based on your quality needs

Download your compressed PDF with reduced file size

Common Use Cases

Compress a 45MB scanned invoice to 3.2MB (93% reduction) to meet email attachment limits

Reduce a 28MB presentation with embedded images to 8MB (71% reduction) for file sharing

Compress multiple scanned receipts (5MB each) to 800KB each (84% reduction) for archiving

Reduce a 15MB PDF report with charts to 4.5MB (70% reduction) for client delivery

Compress a 60MB scanned book chapter to 12MB (80% reduction) for mobile reading

Reduce a 22MB portfolio PDF to 5MB (77% reduction) for website upload

Compress a 35MB research paper with images to 8MB (77% reduction) for email submission

Features

Three compression levels: Fast (30-50% reduction), Medium (50-70% reduction), Maximum (70-90% reduction)

Preview compression estimates before processing

Maintains PDF quality while reducing file size

Process files up to 100MB (limited by browser memory)

100% private—all processing happens in your browser

No registration or file uploads required

Works offline after initial page load

Limitations & Constraints

Maximum file size: 100MB (browser memory limit). For larger files, use desktop software like Adobe Acrobat or split the PDF first.

Password-protected PDFs must be unlocked first. Use our PDF Unlock tool before compression.

Complex vector graphics may not compress as effectively. Expect 10-30% reduction for vector-heavy PDFs.

Very old PDFs (pre-2000) may have compatibility issues. Try updating the PDF in a modern PDF editor first.

Batch processing: Process one file at a time. For 10+ files, consider desktop software for efficiency.

Troubleshooting

Compression fails with 'File too large' error

Solution: Reduce file size first by splitting the PDF or removing unnecessary pages. If the PDF is over 100MB, use desktop software. Check your browser's available memory—close other tabs and applications. Try a different browser (Chrome typically handles larger files better). Prevention: Keep files under 50MB for best results. For very large PDFs, split into smaller chunks first.

Compressed PDF looks blurry or low quality

Solution: The compression level may be too aggressive. Unfortunately, our tool doesn't offer quality settings—it uses optimized compression. For better quality control, use desktop software like Adobe Acrobat with quality sliders. Alternatively, try compressing only specific pages that don't need high quality. Prevention: Preview the compressed file before downloading. If quality is unacceptable, use desktop software with quality controls.

Browser crashes when processing large PDF

Solution: Close other browser tabs and applications to free up memory. Try a different browser (Chrome handles large files better than Firefox). Split the PDF into smaller chunks (10-20 pages each) and compress separately. If crashes persist, use desktop software for files over 50MB. Prevention: Keep files under 50MB. Check available system memory before processing large files.

Compressed PDF won't open in my PDF reader

Solution: This is rare but can happen with corrupted files. Try re-compressing the original PDF. If the original PDF opens fine, the issue may be browser-specific—try a different browser. As a last resort, use desktop software to compress the original PDF. Prevention: Ensure the original PDF opens correctly before compression. Use modern PDF readers (Adobe Reader, Chrome PDF viewer).

Compression takes too long or seems stuck

Solution: Large files (over 30MB) can take 30-60 seconds to process. Check your browser's task manager to see if it's still processing. If it's been more than 2 minutes, refresh the page and try a smaller file or split the PDF. Ensure you have a stable internet connection (for initial page load). Prevention: Keep files under 30MB for faster processing. Close other applications to free up system resources.