PDF Compressor

Compressing PDF files is essential for professionals, students, businesses, and anyone who needs to reduce document sizes for faster email delivery, lower storage costs, improved website performance, and easier file sharing. Whether you need to shrink a large contract before emailing it to a client, compress a multi-page report for upload to a document management system, reduce the size of a scanned document for cloud storage, or optimize a portfolio PDF for web publishing, the PDF Compressor delivers professional-grade results instantly and securely.

The PDF Compressor uses a sophisticated two-stage approach to reduce file size while preserving document readability. Each page is first rendered at an optimal resolution using Mozilla's PDF.js library, then re-encoded as a highly efficient JPEG image that is reassembled into a clean, compact PDF document. This approach achieves significant size reductions — often 50-90% — by applying JPEG compression to the visual content of each page, which is particularly effective for scanned documents, image-heavy PDFs, presentations, and reports that contain photographs or graphics.

The tool's three-tier compression system gives you precise control over the quality-to-size trade-off. The Basic range (67-100%) delivers high-fidelity output suitable for archiving and printing where near-original quality is important. The Medium range (34-66%) provides an excellent balance for standard document sharing, email attachments, and online publishing. The Advanced range (1-33%) achieves maximum file size reduction ideal for uploads to bandwidth-limited systems, cloud storage, and quick sharing. All processing happens entirely in your browser using client-side JavaScript — no files are uploaded to any server, guaranteeing complete privacy and security for your sensitive documents.

Important trade-off: Because each page is flattened to a JPEG image, the compressed PDF will not support text selection, search, copy-paste of text, or interactive elements like hyperlinks, bookmarks, and form fields. This approach prioritises maximum size reduction and is best suited for scanned documents, image-heavy files, and read-only sharing where selectable text is not required.

1. Select your PDF: Click the upload area or drag and drop a PDF file onto the drop zone. The tool accepts PDF files up to 50 MB in size.
2. Review the details: Once the file loads, you will see the file name, size, page count, and a thumbnail preview of the first page. This allows you to confirm you have selected the correct file before compressing.
3. Adjust compression level: Use the intuitive slider to choose your preferred compression — Advanced (1-33% for maximum reduction), Medium (34-66% for balanced quality and size), or Basic (67-100% for high-fidelity output). The current compression label and percentage are displayed in real-time as you adjust.
4. Compress: Click the "Compress PDF" button (the button shows the page count for multi-page documents). A 5-second animated progress spinner appears while each page is rendered and compressed. The spinner shows real-time progress and the current page being processed.
5. Download the result: Once complete, you will see a detailed comparison showing the original file size versus the compressed file size along with the exact percentage reduction and space saved. Download the compressed PDF directly, share it via supported applications using the native share feature, or click "Compress Another" to start over with a new file.
6. Pro tip: For scanned documents and image-heavy PDFs, Medium compression (50-60%) typically achieves 60-80% file size reduction while keeping text readable and graphics clear. Use Basic (80-90%) for documents that will be printed or archived long-term. Advanced (20-30%) is ideal for email attachments and quick sharing. Note: simple text-only PDFs that are already small may see a size increase — the tool shows an honest before/after comparison so you can decide.