Compress PDF – Reduce PDF File Size Instantly

Shrink PDF file size for easier sharing and faster uploads. Processing runs entirely in your browser.

Unlike online PDF compressors, files are processed entirely in your browser.

Select PDF file

Drag & drop PDF here or click to browse

How to Compress PDF:

Upload PDF

Click "Select PDF" or drag & drop your PDF file

Choose Quality

Select compression quality (Low, Medium, High)

Compress & Download

Click "Compress PDF" and download the compressed file

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A PDF compressor is essential for professionals, students, and businesses who need to reduce PDF file sizes for easier sharing, faster uploads, or storage optimization. This free online compress PDF tool instantly reduces PDF file sizes by compressing images, removing metadata, and optimizing document structure, making it easy to share large PDFs via email, upload to websites, or archive document collections. Whether you're compressing scanned documents, image-heavy PDFs, or large reports, this PDF file size reducer provides fast, secure compression without requiring software installation or account creation.

Perfect for professionals sharing large documents, students submitting assignments, businesses optimizing file storage, designers compressing portfolios, and anyone who needs to reduce PDF size or shrink PDF files. This PDF optimizer processes all files locally in your browser—no data is sent to servers, ensuring complete privacy and security. No signup required, no usage limits, and works on all devices. For related PDF needs, check out our merge PDF and split PDF tools.

What Is a PDF Compressor?

PDF files can become large due to high-resolution images, embedded fonts, metadata, and uncompressed content. While large PDFs preserve quality, they can be difficult to share via email, upload to websites, or store efficiently. PDF compression reduces file sizes by optimizing images, removing unnecessary metadata, and compressing document structure while maintaining readability and visual quality.

Why PDF compression is needed: Many workflows require smaller file sizes for email attachments, web uploads have size limits, storage optimization reduces costs, faster sharing improves collaboration, and mobile devices benefit from smaller files. Compressing PDFs makes documents more versatile and usable across different platforms and applications.

What problems it solves: This compress PDF online tool solves common problems like email attachment size limits, slow file uploads, storage space constraints, mobile device limitations, and web form submission restrictions. It eliminates the need for expensive software, complex installations, or manual workarounds, making PDF compression accessible to everyone.

When to Use a PDF Compressor

Email Attachments

Compress PDFs to meet email attachment size limits. Most email providers have size restrictions (typically 10-25MB), and compressing PDFs ensures your documents can be sent successfully. Perfect for sharing reports, invoices, or documents via email without exceeding size limits.

Web Uploads

Reduce PDF sizes for faster web uploads and to meet website file size restrictions. Many online forms, job applications, and document submission systems have file size limits. Compressing PDFs ensures successful uploads and faster transfer times.

Storage Optimization

Compress PDFs to save storage space on devices, cloud storage, or servers. Large PDF collections can consume significant storage space, and compression helps optimize storage while maintaining document quality. Essential for archiving and long-term storage.

Mobile Sharing

Compress PDFs for easier sharing on mobile devices and faster downloads. Mobile networks can be slower, and smaller files download faster and use less data. Perfect for sharing documents on the go or in areas with limited connectivity.

Document Archiving

Compress PDFs for efficient document archiving and backup. Large PDF collections can be expensive to store and backup. Compressing PDFs reduces storage costs while maintaining document quality, making archiving more efficient and cost-effective.

How to Use This PDF Compressor (Step-by-Step)

Uploading PDF

Click "Select PDF" or drag and drop your PDF file into the upload area. The tool supports PDFs up to 50MB in size. All processing happens locally in your browser—nothing is uploaded to servers, ensuring complete privacy and security.

Choosing Compression Quality

Select your preferred compression quality: Low (maximum compression, smaller file size), Medium (balanced compression and quality), or High (light compression, best quality). The quality setting affects the balance between file size reduction and image quality preservation.

Compressing PDF

Click the "Compress PDF" button to start compression. The tool processes images within the PDF, removes metadata, and optimizes the document structure. Processing typically takes a few seconds to a minute, depending on PDF size and complexity.

Viewing Results

After compression completes, view the results showing original size, compressed size, and reduction percentage. The compression ratio indicates how much file size was reduced. Higher ratios mean more space saved.

Downloading Compressed PDF

Click "Download Compressed PDF" to save the compressed file to your device. The filename includes "-compressed" to help you identify the compressed version. Original PDF files remain unchanged on your device.

Pro Tip: Use "Low" quality for maximum compression when file size is critical. Use "High" quality when you need to preserve image quality. PDFs with many images typically compress better than text-only PDFs. For best results, compress PDFs before sharing or archiving. Combine this tool with our merge PDF tool to combine and compress multiple PDFs at once.

Frequently Asked Questions

Is this tool free?

Yes, this PDF compressor is completely free to use with no signup required. There are no usage limits, no hidden fees, and no account creation needed. The tool works entirely in your browser, ensuring fast performance and complete privacy. All compression happens locally—no data is sent to servers.

Does it work on mobile?

Yes, this PDF compressor is fully responsive and works on all devices, including smartphones and tablets. The interface adapts to smaller screens, and all features are available on mobile browsers. Perfect for compressing PDFs on the go.

Are my files secure?

Yes, your files are completely secure. All PDF processing happens locally in your browser—no files are uploaded to any server. Your PDFs never leave your device, ensuring complete privacy and security. The tool uses client-side JavaScript libraries to process PDFs entirely on your computer.

How much can PDFs be compressed?

Compression results vary depending on the PDF content. PDFs with many images typically compress better (30-70% reduction), while text-only PDFs may see minimal compression (5-15% reduction). The compression quality setting (Low, Medium, High) affects the balance between file size and quality.

Will compression affect PDF quality?

Compression may slightly reduce image quality within the PDF, especially with the 'Low' quality setting. The 'High' quality setting maintains better image quality while still reducing file size. Text and vector graphics are generally unaffected by compression.

What file size limits apply?

PDFs up to 50MB and 100 pages are supported. We limit size and page count so the tool stays stable in your browser. For larger or longer documents, split the PDF first, then compress each part.

Limitations & Tips

File and Page Limits

PDFs up to 50MB and 100 pages are supported. We limit these so the tool stays stable in your browser. For larger or longer documents, use our split PDF tool first, then compress each part.

Compression Results

Compression results vary depending on PDF content. PDFs with many high-resolution images typically compress better (30-70% reduction), while text-only PDFs may see minimal compression (5-15% reduction). The compression quality setting affects the balance between file size and quality.

Image Quality

Compression may slightly reduce image quality within the PDF, especially with the "Low" quality setting. The "High" quality setting maintains better image quality while still reducing file size. Text and vector graphics are generally unaffected by compression.

Security Handling

All PDF processing happens locally in your browser using JavaScript libraries. No files are uploaded to servers, and no data is transmitted over the internet. Your PDFs remain completely private and secure. The tool doesn't store, save, or access your files beyond the compression process.

Best Practices

For best results, ensure your PDFs are not corrupted before uploading. Use "Low" quality for maximum compression when file size is critical. Use "High" quality when you need to preserve image quality. PDFs with many images typically compress better than text-only PDFs. For comprehensive PDF management, combine this tool with our merge PDF, split PDF, and other PDF utilities for a complete PDF workflow.