Compress PDF Files - Reduce Size Securely & Online

Optimize your PDF documents by reducing their file size for easier emailing and storage. Choose from predefined levels or customize compression settings. This tool is fast, free, and processes everything securely in your browser—no file uploads required.
Secure & Private: PDF operations are processed entirely in your browser.

Your Free and Secure PDF Compression Tool

Upload PDFs to Compress
Upload one or more PDF files to reduce their size.

Click to upload or drag and drop

Max file size: 10MB. Accepted: .PDF, PDF

How to Compress a PDF in 3 Simple Steps

1. Upload PDFs
Click the upload area or drag and drop your PDF file(s). You can compress multiple documents at once.
2. Choose Settings
Select a compression level (like High, Medium, or Low) or define custom settings to balance size and quality.
3. Compress & Download
Click "Compress." Your new, smaller PDFs are processed instantly in your browser and are ready for download.

What To Do Next With Your Compressed PDF?

Organize Pages
Need to make final adjustments? Reorder, rotate, or delete pages from your PDF.
Edit PDF
Add text, images, or shapes to your optimized document.
Watermark PDF
Protect your document by adding a custom text watermark like "DRAFT" or "CONFIDENTIAL".

Frequently Asked Questions

Is it safe to compress my PDFs with One23PDF?

Yes, completely. One23PDF performs all compression directly in your browser. Your files are never uploaded to our servers, ensuring your data remains 100% private and secure.

What compression levels are available?

We offer several presets: High (maximum compression, may reduce image quality), Medium (a good balance), and Low (minimal compression, best quality). You can also use 'Custom' settings for fine-tuned control.

Will compressing my PDF reduce its quality?

Compression primarily targets images and unused data within the PDF. Text quality is generally unaffected. The impact on image quality depends on the compression level you choose. High compression will have a more noticeable effect than low compression.

Why didn't my file size get much smaller?

If a PDF has already been optimized or contains mostly text with few images, the potential for size reduction is limited. Our tool works best on unoptimized PDFs with large images.

Further Reading & Resources

The Security Risks of Using Online PDF Tools

An insightful article on why browser-based processing (like One23PDF uses) matters for your data security when handling documents online.

The Rise of Browser-Based PDF Editors: Security Meets Convenience

Learn more about the advantages of client-side PDF manipulation, focusing on both security and user convenience.