PDF Compress

Completely free. No registration required, no usage limits. All processing happens locally in your browser with no server costs, so it can remain free forever.

No. This tool processes everything locally in your browser — your file is never uploaded to any server. Compared to traditional online tools, this approach is more secure, faster, and unaffected by network speed.

You can control the output size by choosing compression levels. "Recommended" mode typically achieves 50-70% reduction, while "Extreme" mode can reach 70-90%. Try different settings for precise control.

The "Recommended" mode uses higher DPI and quality settings with virtually no visible difference, suitable when clarity matters. For truly lossless optimization, consider a PDF optimizer rather than a compression tool.

No. This is a pure web application that works in your browser. Supports Chrome, Edge, Firefox, Safari and other major browsers. No plugins or software installation needed.

Upload your PDF and select a compression level. The tool automatically optimizes image encoding, reduces resolution, and removes redundant data to effectively reduce file size.

No. Compression only optimizes image encoding and removes redundant data. All text, images, and layout remain unchanged.

It depends on compression settings. The "Recommended" mode maintains high clarity, while "Extreme" mode reduces DPI and image quality for smaller file size.

"Recommended" mode: DPI 120, quality 40% — maintains good clarity, suitable for daily use. "Extreme" mode: DPI 50, quality 4% — smallest file size but lower clarity, suitable when image quality is not critical.

No file size limit. Since all processing happens locally in your browser, larger files take longer. We recommend processing large files on a device with good performance.

Depends on file size, page count, and device performance. Usually a few seconds to tens of seconds. The tool uses multi-threaded parallel processing for faster speeds in modern browsers.

The file is automatically downloaded to your browser's default download location after compression completes. No manual action needed.

Not recommended. The first compression removes most redundant data. Multiple compressions have diminishing returns and may even increase file size due to re-encoding.

No. This tool primarily compresses images in the PDF. Embedded videos, audio, and other multimedia files are not compressed.

Completely safe. All processing happens locally in your browser. Your file is never uploaded to any server, and data is automatically cleared after processing completes.