How to Reduce PDF File Size (4 Methods That Work)

A PDF is large for one main reason: images. Text and vector graphics take very little space, while a single photo or a scanned page can account for megabytes. Knowing that tells you where to look.

1. Re-export with a smaller setting

If you still have the source document, the best fix is at the source. Word, Google Docs, Pages and LibreOffice all offer an export option such as "minimum size" or "reduce file size". Compress images in the document itself first, then export.

2. Compress the finished PDF

When the source is gone, use Compress PDF. Light compression only tidies the file structure and keeps text selectable, but savings are usually small. Strong compression renders pages as images at a chosen resolution and quality, which can shrink scans and photo-heavy files dramatically. The trade-off is that text in the result can no longer be selected or searched.

A quick guide to the strong settings:

• 150 dpi, high quality: still fine for printing
• 110 dpi, medium: good for screens and email
• 80 dpi, low: smallest, text may look soft

3. Remove pages you do not need

Cover sheets, blank pages and duplicate scans add weight. Take them out with Delete PDF pages before compressing.

4. Send it in parts

If one file has to stay high quality, cut it into chunks with Split PDF and send several attachments instead of one.

What will not shrink

A text-only PDF of a few hundred kilobytes is already efficient. If compression returns the original, that is the tool refusing to make the file bigger, not a failure.