A PDF can look perfectly ordinary and still be too large for an email attachment, application portal, or government form. The usual cause is not the number of pages. It is the amount of image data, embedded fonts, and unused document information stored inside the file.
The right way to shrink it depends on where the file is going. A text-heavy contract needs crisp lettering, while a scanned receipt can usually tolerate stronger image compression. Start with the destination limit, then use the lightest setting that gets below it.
Check the limit before you compress
Look for the exact maximum on the upload form or in the email provider's attachment rules. A form asking for a file under 1 MB needs a different approach from an inbox that accepts 20 MB. Knowing the target prevents repeated trial and error.
If the file is only slightly over the limit, use balanced compression first. Strong compression is better reserved for image-heavy scans or strict limits because it may soften fine details.
- For general sharing: favour balanced compression.
- For archiving or print: use lossless compression when possible.
- For a fixed portal limit: enter the target size and check the result.
Compress the PDF in four steps
Open PDFNova's Compress PDF tool and add the document. Select a compression level based on your target. Balanced is the safest starting point; strong produces a smaller file, while target-size mode keeps trying to fit a limit you provide.
Run the tool and download the new PDF. Keep the original until you have opened the smaller copy and checked the pages that matter most.
- Add one PDF from your device.
- Choose balanced, strong, lossless, or target-size mode.
- Start compression and download the result.
- Open the output and inspect text, signatures, charts, and small print.
What to inspect after compression
Do not judge the result from file size alone. Zoom into scanned text, thin lines in charts, QR codes, signatures, and any page containing small labels. These areas reveal quality loss sooner than large headings or simple paragraphs.
If the document became hard to read, go back to the original and select a gentler level. Recompressing an already compressed copy compounds image degradation, so each new attempt should begin with the source file.
When compression is not enough
A PDF made from hundreds of photographs may remain large even after strong compression. In that case, remove pages the recipient does not need, split the document into permitted sections, or recreate oversized source images at a sensible resolution before exporting again.
For email, you can also send a trusted cloud link instead of an attachment. For formal upload portals, splitting is only appropriate when the portal accepts more than one file, so check its instructions first.
Published by PDFNova on August 8, 2026. This guide provides general information; follow your organisation's requirements for sensitive or regulated documents.