PDF Compress

What is PDF Compress?

PDF Compress reduces PDF file size by optimizing structure and compressing embedded images. Large PDFs—often from scans, high-res exports, or merged documents—can be difficult to email or store. This tool shrinks them while preserving readability. All processing runs client-side in your browser; your files never leave your device. No upload, no signup, complete privacy.

The tool uses two strategies: first, lossless re-packing (optimizing the PDF structure) and second, image-based compression (rasterizing pages at lower quality). It automatically picks whichever produces the smallest file. Presets (Email, Web, Print) set quality and DPI for common use cases. Advanced options include DPI control, strip metadata, and grayscale for maximum size reduction.

How to Use PDF Compress

1. Click a preset (Email, Web, Print) or use the default Web preset. Adjust the quality slider (40–95%) and fine-tune in Advanced.
2. Click the dropzone or drag and drop a PDF file. Up to 50 MB.
3. Open Advanced to set DPI target (72–300), enable Strip metadata, or Grayscale for extra compression.
4. Click Compress PDF. The tool tries lossless optimization first, then image-based compression, and picks the smallest result.
5. Review the before/after stats (Original, Compressed, Saved %). Click Download PDF when ready.

Tips & Best Practices

Use Email preset for small attachments; Print for high-quality output. Lower DPI reduces file size but may blur text—150 DPI is usually fine for screen viewing. Enable Grayscale for text-heavy documents to save significant space. Strip metadata removes author, title, and timestamps. Already-optimized PDFs may not shrink further—the tool will indicate when no reduction is possible. Press Ctrl+Enter to compress and Escape to clear. If you need to extract pages first, use PDF Split.

When to Use This Tool

Use PDF Compress when reducing file size for email, storage, or web upload. Ideal after merging PDFs with PDF Merge or splitting with PDF Split. If the merged result is too large, compress it. If you only need certain pages, split first to reduce size before compressing. All ToolCrux PDF tools run client-side—your documents stay private.