Free Online Compress PDF
Reduce PDF file size with adjustable quality and image resolution.
Upload a PDF to compare its original and compressed size.
Lower quality produces a smaller file but softer images and text. Used only in stronger compression mode.
Upload a PDF to begin.
Lossless cleanup rewrites the PDF structure without changing text, images, or page appearance. Savings vary and can be small for files that are already optimized.
About the Compress PDF Tool
PDF files often grow much larger than their content requires. High-resolution photos, duplicate resources, and verbose internal structure can push a simple report past the upload limit of an email inbox or a web form. This compressor offers two approaches in the same page: a safe structural cleanup that keeps every text character and image intact, and a stronger rasterizing mode that rebuilds the document from JPEG page images.
Lossless cleanup vs. stronger compression
Lossless cleanup loads the PDF and saves it again with compressed object streams. Fonts, text, links, and image data are not deliberately discarded. Because the original file may already be well optimized, the reduction can be modest or even zero. Stronger compression renders each page with PDF.js at your chosen resolution and embeds the result as a JPEG, then rebuilds the PDF with pdf-lib. That usually produces a much smaller file, especially for scanned pages and photo-heavy documents.
What rasterizing changes
- Text stops being text: Selectable text becomes part of an image, so search, copy, and reflow no longer work.
- Links and form fields disappear: Only the visible page is captured.
- Sharpness depends on resolution: 108 dpi is a good balance for screen reading; 144-216 dpi is better for printing.
- Small text can soften: Quality below 60% may make fine print hard to read. Check the result before sharing.
Frequently asked questions
Why did my PDF get larger after lossless cleanup?
Re-saving can change how resources are packed. If the source was already optimized, the new file may be about the same size or slightly bigger. Try the stronger mode or reduce the render resolution.
Is stronger compression suitable for contracts or invoices?
It is suitable when the document only needs to be read or printed. Keep the original if you need selectable text, searchable records, accessible tagging, or working hyperlinks.
Are my files uploaded?
No. PDF parsing, page rendering, JPEG encoding, and file creation all happen in your browser. Your document never leaves your device.