Compress PDF
Reduce your PDF document file size directly in your browser. Choose the optimal balance between visual quality and file size without sending your data to any server.
About PDF Compression
Whether fitting within strict email attachment quotas or university application portals, reducing PDF file size is a daily necessity. Solasu's PDF Compressor optimizes embedded raster image XObjects and compresses document streams directly inside a Web Worker. Because processing occurs entirely client-side on your device, sensitive financial records, agreements, and personal IDs remain completely private.
Three Simple Presets & Flexible Advanced Settings
Get started immediately with Light, Standard, or Strong presets. The default 'Standard' preset provides an ideal compromise between sharp visuals and substantial byte reduction.
Need precise control? Expand Advanced Settings to configure maximum image dimension caps, JPEG quality sliders (1–100), grayscale conversion for monochrome documents, and metadata removal.
Preserves Text Searchability and Page Geometry
Unlike crude converters that flatten entire pages into blurry images, Solasu targets only the heavy raster bitmap objects inside your PDF.
Your vector fonts, selectable text streams, page dimensions (MediaBox), and page sequences remain intact, allowing full text selection and copying in the compressed file.
Sequential Batch Processing & ZIP Archive Download
Add multiple PDF files at once. Documents are processed sequentially one by one, preventing browser memory spikes and tab crashes on mobile devices.
Download individual files or grab all compressed documents simultaneously with a single click using the primary ZIP download button.
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Frequently Asked Questions
Is this PDF compressor free to use?
Yes, Solasu is 100% free with no registration, no file count restrictions, and no watermarks added to your documents.
Are my PDF files uploaded to any server?
No. All parsing, image recompression, and document serialization happen strictly inside your browser via Web Workers and Web APIs. Your PDF files never leave your computer or phone.
How much can the file size be reduced?
Reduction depends on document contents. PDFs containing high-resolution camera photos or scans can shrink by 50% to 80%. Documents that already consist mostly of optimized text will show minimal change. Real measured byte reduction is reported on the result screen.
Does compression degrade document quality?
Preset settings control image downsampling and JPEG quality. 'Light' retains maximum visual clarity, while 'Strong' maximizes byte savings. Text, fonts, and vector paths are never rasterized and stay completely sharp.
Can I compress scanned PDFs?
Yes. Scanned PDFs typically contain large high-resolution JPEG or PNG images and benefit the most from our image optimization pipeline.
Can I compress text-only PDFs?
Text-heavy PDFs are already very compact. While internal object streams are optimized, file size reduction may be negligible. The tool safely reports actual measured size.
Can a compressed PDF become larger than the original?
If an input PDF is already highly compressed, re-saving might slightly increase its size. Solasu detects this honestly, warns you that the file could not be reduced, and lets you download the original file.
Are hyperlinks inside the PDF preserved?
Because our engine modifies image XObjects rather than page content streams, standard document hyperlinks and annotations are generally preserved. Always verify critical links after downloading.
Are interactive form fields (AcroForms) kept?
Form field structures and values are kept intact. Complex dynamic JavaScript forms should be checked after processing.
Are document bookmarks and outlines retained?
Yes, document outline trees and bookmarks are preserved throughout the compression process.
Is PDF/A archive compliance maintained?
Image re-encoding and metadata adjustments may affect strict PDF/A compliance standards. Please verify compliance if submitting to strict legal archival repositories.
Can I compress large PDFs or multiple files?
Yes. Batch processing works sequentially to protect device memory. Soft warnings appear for documents over 100 pages or 50 MB to ensure device stability.