What is Compress PDF?
Compress PDF reduces the file size of a PDF so it is easier to email, upload to a portal or store. It re-optimizes images and internal structure while keeping the text readable, and you pick how aggressive the compression should be.
Common uses
- Email attachment limits. Shrink a large PDF so it fits under the size limit of your mail provider.
- Online form uploads. Government and college portals often cap uploads at a few MB — compress first, then submit.
- Scanned documents. Scans are mostly large images; compression brings them down dramatically.
- Saving storage. Archive long reports and presentations in a fraction of the space.
| Extreme | Smallest file, lower image quality — good for screen reading and tight upload limits |
|---|---|
| Recommended | Good balance of size and quality — the default |
| Less compression | Highest quality, smaller reduction — good when the file may be printed |
| Input / output | PDF in, PDF out |
| Size limit | 50 MB per file |
| Sign-up | Not required |
Tips for best results
- Start with Recommended. Only move to Extreme if the file is still too big.
- A PDF made mostly of text will not shrink much — the saving comes from images.
- Keep your original: compression is lossy for images and cannot be reversed.
- For a scan that you also need to search, run OCR PDF first, then compress.