PDF Compressor
Use PDF Compressor, review the result, and keep the original until the output is checked.
How to use PDF Compressor
- Select PDF Files and load the documents to shrink; compression starts as soon as a file is read, and again whenever you change an option.
- Start with the default Compression Level, then try High only if the result is still too large.
- Leave Reduce Image Quality ticked and lower Image Quality from 60 gradually - each step trades detail in photographs for bytes.
- Compare the before and after figures beside each file before Download All writes <name>_compressed.pdf.
What PDF Compressor actually does to your file
What happens depends on what the file already is. A PDF built from text and vectors keeps its text layer and usually shrinks only a little, because most of its size is the page structure rather than pixels. A scan or a photo-heavy document is redrawn page by page at a fixed resolution and rebuilt from JPEG images, which can save real space but makes the output unsearchable and unselectable - and can leave the physical page dimensions larger than the original. So a percentage near zero, or even a negative one, is normal for a text PDF; the meaningful case is a scanned file you no longer need to search.
PDF Compressor FAQ
What does PDF Compressor do?
This tool allows you to compress PDF files online, shrinking their size without compromising quality. It’s free, fast, and easy to use. Perfect for handling large PDFs quickly.
Which files work with PDF Compressor?
This category commonly supports PDF and exported JPG or PNG pages. Use the accepted file types shown in the uploader, because support varies by browser and by the engine behind each tool.
Does compressing reduce the quality?
Yes, size comes from discarding detail. Start near the middle of the quality range and look at the result; if it is not small enough, lower the quality rather than re-compressing the same file several times, because each pass loses more.
Will my original file be changed?
No. The work is done on a copy in this tab by pdf.js and pdf-lib, and the result arrives as a separate download, so your original is still there if you need it.
How is my file processed?
It is not uploaded. The processing is done locally by pdf.js and pdf-lib, so the practical ceiling is your device's memory and the limit shown beside the uploader - no queue, no account, no copy on a server.
Is the PDF Compressor free?
Yes. The PDF Compressor is free with no trial limit, subscription, or watermark on downloads. You can use it for personal and commercial projects without creating an account.