How to Compress a PDF Online
A practical guide to reducing PDF file size while balancing readability, image quality, and compatibility.
Why PDF files become large
PDFs often contain scanned pages, photographs, screenshots, embedded fonts, and other assets. A document with a few text paragraphs can stay small, while a scanned document can become many megabytes because every page contains image data.
Compression works by reducing the amount of data required to represent those assets. The best settings depend on whether you need maximum readability, a smaller attachment, or a balance between the two.
How to compress a PDF
Open the PDF Compressor, select your document, choose a compression level, and start processing. When processing finishes, compare the original and output sizes before downloading.
- • Use a stronger setting when file size is the main priority.
- • Use a balanced setting for everyday sharing and email attachments.
- • Use a clearer setting when screenshots or scanned text need to remain easy to read.
What to check after compression
Open the resulting file before sending it. Check small text, scanned pages, tables, signatures, and any pages that contain important images. A smaller PDF is not automatically a better PDF if important information becomes difficult to read.