OnlineFreeToolBoxHow-to guide
How to Compress a PDF
A PDF can be far larger than it needs to be, which makes it slow to email or upload. Compressing a PDF re-saves it more compactly so the file gets smaller while the pages look the same. This guide shows how to compress a PDF for free, in your browser — no sign-up, no upload, and your file never leaves your device.
How to Compress a PDF — step by step
- Choose a PDF with “Select PDF file”.
- Read the options panel, which explains what re-saving does and what it does not do.
- Press “Compress PDF”.
- Download the compressed file, named compressed.pdf.
Tips
- Pick the right level. Less keeps the most quality, Recommended is a good middle ground, and Extreme gives the smallest file.
- Do not expect miracles on scanned PDFs. Re-saving removes overhead but does not recompress scanned images, so a scan-heavy file may barely shrink.
- Compressing twice rarely helps. Once the overhead is removed, a second run usually finds nothing more to save.
Frequently asked questions
How much smaller will my PDF get?
It depends on the file. Re-saving removes some overhead, but it does not recompress scanned images like a desktop tool.
Can I compress a PDF more than once?
Re-saving an already compressed PDF rarely shrinks it further, because the overhead has already been removed. If a second run gives no reduction, the file is already as compact as browser re-saving can make it.
Will compression change how my PDF looks?
No. Pages, text and images are preserved; only the file's internal structure is re-saved more compactly.