How to optimize a PDF for web sharing

Start with the intended use

A PDF intended for on-screen reading does not need the same image resolution as a document prepared for professional printing. Define whether users will read, download, print, archive, or search the file. That decision determines how much compression is appropriate.

Optimize the images first

Photographs and scans usually account for most of a PDF’s size. Crop unused areas before placing an image, resize it to an appropriate effective resolution, and apply moderate compression. Screenshots and diagrams with fine text need more conservative settings than photographs.

If the document contains scanned pages, consider optical character recognition so readers can search and select text. Review the recognized text for errors, particularly in names, numbers, and tables.

Preserve real text and links

Do not rasterize an entire document merely to reduce its size. Real text remains sharper, searchable, accessible, and often smaller than a picture of the same page. Preserve working hyperlinks, headings, bookmarks, and reading order when they are relevant to the audience.

Handle fonts carefully

Embedding fonts helps a PDF look consistent on other devices, but embedding a complete font family can add unnecessary weight. Subsetting includes only the characters used in the document. Verify that the license permits embedding and that special characters display correctly.

Remove what readers do not need

• Unused page objects and duplicate resources
• Hidden layers that are not part of the published file
• Oversized embedded thumbnails
• Unnecessary editing history or attachments
• Metadata that has no publishing purpose

Test the optimized PDF

1. Open it in more than one PDF viewer.
2. Zoom into charts, screenshots, and small type.
3. Search for a phrase to confirm text remains selectable.
4. Activate links and bookmarks.
5. Check accessibility reading order when required.
6. Download it over a slower connection and test on a phone.