How to Reduce PDF File Size Before Uploading

A text-heavy PDF may already be compact, while a scanned document can contain a full-resolution image on every page. That difference matters because stronger compression may save significant space on an image-heavy file but produce little improvement on an already optimized document.

Before compressing a document used for an official process, keep the original PDF in a safe location. The source remains useful if the compressed copy loses quality or an internal feature is changed.

Start with a balanced setting when readability and fidelity matter. Stronger settings can be appropriate when a strict upload limit is more important, but the resulting document should be opened and checked before use.

Image-based compression can affect selectable text, searchable content, annotations, forms, accessibility or other PDF features. A smaller file is not automatically a better file.

Check the final file size, page count and visual appearance. Open several pages, including pages with small text, tables, signatures or images. For documents with digital signatures or certifications, do not assume that a transformation preserves the original signature state.

When the destination specifies a maximum file size, compare the result against that exact limit rather than relying on the compression mode name.