Free Online PDF Compressor — Reduce PDF File Size
Reduce the size of your PDF files with our free online PDF compressor. Upload any PDF and our tool recompresses the internal data streams, removes unnecessary metadata, and uses modern object streams to produce a smaller file with no visual quality loss. All processing happens locally in your browser — your files never leave your device.
Upload the PDF file you want to compress.
Click the compress button — the tool processes your file automatically.
Download your compressed PDF and see exactly how much space was saved.
Tips for Compressing PDFs
- The tool uses lossless compression — your PDF's visual quality and text selectability are fully preserved.
- The best results come from PDFs with embedded images. The tool recompresses streams to optimize both text and image data.
- If you need more aggressive compression, consider using our PDF to Image tools to convert pages to JPEG images, then rebuild a new PDF.
Frequently Asked Questions — PDF Compressor
Is the PDF compressor free?
Yes, completely free. No registration, no hidden charges, and no watermarks. All processing happens locally in your browser.
How does the compression work?
The tool loads your PDF using pdf-lib, recompresses the internal object streams, removes unnecessary metadata (title, subject, creator, producer), and saves with modern cross-reference object streams. This reduces file size without any visual quality loss.
How much can I reduce the file size?
The compression ratio depends on the original PDF. Text-heavy PDFs typically compress 10-30%. PDFs with embedded high-resolution images may see more significant reductions as the image streams are recompressed.
Will the compressed PDF look the same?
Yes — the compression is lossless, so the visual quality is identical to the original. All text, images, and layout are preserved exactly as they were.
Does the tool remove text or images?
No. The tool only removes unnecessary metadata (like author name and software version) and recompresses the internal data streams. All visible content — text, images, links, bookmarks, and form fields — is fully preserved.
Is my PDF file secure?
Yes. All processing happens entirely in your browser using WebAssembly. Your PDF file never leaves your device — no upload to any server.
What PDF features are preserved?
All features are preserved including text, images, links, bookmarks, form fields, and annotations. The tool performs lossless stream recompression and metadata cleanup without modifying the visible content or interactive elements.