PDF Compressor - Reduce PDF File Size Online
Compress PDF files online for free while maintaining quality. Reduce file sizes by up to 90% with advanced compression. Perfect for email, web, and storage optimization.
Upload PDF to Compress
Drag and drop your PDF file or click to browse. Maximum file size: 50MB. All processing happens in your browser.
Drop your PDF here or click to browse
Supports PDF files up to 50MB
Privacy Protected
All compression happens locally in your browser. Your PDF never leaves your device.
High Quality
Advanced compression algorithms maintain visual quality while significantly reducing file size.
Free Forever
Completely free to use with no limits. Compress unlimited PDFs without registration.
How to Compress PDF Files Online
Simple 4-Step Process
- 1Upload your PDF file by clicking or dragging it into the upload area
- 2Adjust compression level (10-100%) - recommended: 75% for balanced quality/size
- 3Choose options: remove metadata, optimize images for additional compression
- 4Click "Compress PDF" and download your optimized file with reduced size
Compression Tips
- For emails: Use 50-70% compression (under 10MB attachments)
- For web: Use 60-75% compression (fast loading, good quality)
- For printing: Use 80-90% compression (high quality maintained)
- For archival: Use 40-60% compression (maximum space savings)
- Always keep: A backup of original high-quality PDF files
Why Compress Your PDF Files?
Email Attachments
Compress PDFs to fit email size limits (typically 10-25MB). Send multiple documents without exceeding attachment restrictions.
Faster Upload & Download
Smaller files upload and download significantly faster, especially important for mobile users or slow connections.
Save Storage Space
Reduce PDF archive sizes by 60-90%, saving valuable disk space on servers, computers, and cloud storage.
Website Performance
Compressed PDFs load faster on websites, improving user experience, SEO rankings, and reducing bandwidth costs.
Form & Portal Uploads
Many online forms, portals, and systems have strict file size limits. Compression ensures your documents are accepted.
Mobile Viewing
Smaller PDFs open faster on mobile devices with limited processing power and data plans, providing better accessibility.
Compression Technology & Privacy
Advanced Compression
- • Smart PDF structure optimization
- • Embedded image compression
- • Metadata removal for size reduction
- • Object stream optimization
- • Font subset embedding
- • Duplicate object elimination
- • Content stream recompression
- • Adjustable quality levels (10-100%)
Supported Features
Privacy & Security
- • 100% client-side processing with pdf-lib
- • No PDFs uploaded to servers ever
- • Complete privacy protection guaranteed
- • No registration or account required
- • Works offline after initial page load
- • GDPR and privacy law compliant
- • No tracking or data collection
- • Files deleted from browser memory
Performance Features
- • Fast browser-based processing
- • Support for files up to 50MB
- • Real-time compression statistics
- • Instant before/after comparison
- • Memory-efficient algorithms
When to Use PDF Compression
Business Documents
Compress reports, proposals, presentations, invoices, and contracts for email distribution and client sharing.
Educational Materials
Optimize textbooks, research papers, assignments, and lecture notes for easier sharing with students and colleagues.
Job Applications
Reduce resume and portfolio sizes to meet application portal limits while maintaining professional quality.
Website Publishing
Compress product catalogs, brochures, whitepapers, and guides for faster website loading and better SEO.
Legal & Government
Optimize legal documents, court filings, and government forms that often have strict size requirements for submission.
Healthcare Records
Compress medical reports, lab results, and patient records for secure transmission while protecting privacy.
Compression Level Comparison Guide
| Compression Level | Quality | File Size Reduction | Best For |
|---|---|---|---|
| High (85-100%) | Excellent - No visible loss | 10-30% | Professional printing, legal documents |
| Balanced (70-85%) | Very Good - Minimal loss | 30-60% | General use, presentations, web publishing |
| Medium (50-70%) | Good - Acceptable quality | 50-75% | Email attachments, mobile viewing |
| Maximum (10-50%) | Fair - Noticeable compression | 70-90% | Archival, low bandwidth, large batches |
Frequently Asked Questions
How does PDF compression work?
PDF compression works by optimizing the internal structure of the PDF file, removing unnecessary metadata, compressing embedded images, and reencoding data streams more efficiently. Our tool uses advanced algorithms to analyze your PDF and apply the best compression techniques while preserving visual quality. The compression happens entirely in your browser using pdf-lib, ensuring your files never leave your device.
How much can I reduce PDF file size?
Compression ratios vary depending on the PDF content. PDFs with many high-resolution images can be compressed by 60-90%, saving significant storage space. Text-heavy PDFs typically compress 20-40%. PDFs already optimized may only compress 5-15%. Our tool shows exact savings before and after compression. Factors affecting compression include image resolution, metadata amount, embedded fonts, and existing compression. Use the compression level slider to balance file size vs quality for your specific needs.
Will compression reduce PDF quality?
Our smart compression maintains visual quality while reducing file size. At high quality settings (80%+), most users cannot detect any difference. Medium settings (60-80%) provide excellent balance between size and quality for most documents. Lower settings (<60%) prioritize file size and may show minor quality loss in images. Text clarity is always preserved regardless of compression level. You can preview results before downloading and adjust settings if needed. For important documents, we recommend 75-85% quality for optimal results.
What types of PDFs can be compressed?
Our compressor works with all standard PDF files including scanned documents, digital PDFs, forms, presentations, ebooks, reports, invoices, contracts, and multi-page documents. It handles PDFs with embedded images, fonts, vector graphics, annotations, hyperlinks, and bookmarks. Maximum file size is 50MB for optimal browser performance. Password-protected PDFs must be unlocked first. PDFs with DRM restrictions cannot be compressed. Supports PDF versions 1.4 through 2.0 (most modern PDFs).
Is my PDF secure when using this tool?
Absolutely! All PDF compression happens entirely in your browser using client-side JavaScript with pdf-lib. Your PDF file is never uploaded to any server, transmitted over the internet, or stored anywhere outside your device. No one - including us - can access your PDF content. This ensures complete privacy for sensitive documents like contracts, financial reports, medical records, legal documents, and personal files. The tool works offline after initial page load. Clear your browser cache to remove any temporary data.
Can I compress multiple PDFs at once?
Currently, the tool processes one PDF at a time for optimal quality control and performance. This ensures each PDF gets individual attention for best compression results and allows you to fine-tune settings per file. You can compress unlimited PDFs sequentially with no restrictions. For batch processing, simply compress one file, download it, and upload the next. This approach prevents browser memory issues with large files and gives you control over each compression. Future updates may include batch processing capabilities.
What compression options are available?
You can customize compression with multiple options: Compression Level slider (10-100%) controls the balance between file size and quality. Remove Metadata option strips author information, keywords, creation dates, and editing software details to save space and protect privacy. Optimize Images option compresses embedded pictures and graphics. Higher compression levels (60-80%) work best for most documents. Maximum compression (10-30%) is ideal for archival or email attachments. High quality (85-100%) preserves all details for professional printing. Adjust settings and recompress until satisfied.
How long does PDF compression take?
Compression time depends on PDF size and complexity. Small PDFs (under 1MB) compress in 1-5 seconds. Medium PDFs (1-10MB) typically take 5-15 seconds. Large PDFs (10-50MB) may require 15-60 seconds. PDFs with many high-resolution images take longer than text-only files. Processing happens in your browser, so speed also depends on your device performance - newer computers with better CPUs compress faster. The tool shows real-time progress during compression. No internet speed limitations since everything runs locally.
Will compression affect PDF functionality?
No, compression preserves all PDF functionality including clickable hyperlinks, internal navigation, table of contents, bookmarks, form fields, digital signatures, annotations, comments, highlights, and embedded attachments. Text remains selectable and searchable. Page structure, layout, and formatting stay intact. Security settings and permissions are maintained. Interactive elements continue working normally. Only file size changes - everything else remains exactly as in the original. The compressed PDF opens in any standard PDF reader like Adobe Acrobat, browser viewers, or mobile apps.
What happens to removed metadata?
When you enable "Remove Metadata", the tool strips non-essential information from the PDF including document title, author name, subject, keywords, creator application, producer software, creation date, modification date, and custom metadata fields. This can save 5-50KB depending on metadata amount and protects privacy by removing identifying information. Critical data like page content, images, text, fonts, links, and formatting are never affected. Metadata removal is optional - disable it if you need to preserve document properties, authorship information, or revision history for legal/compliance purposes.
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