U.S. Department of Energy - Energy Efficiency and Renewable Energy

EERE Communication Standards & Guidelines

Techniques for Optimizing PDFs for Search Engines

This page describes the best practices for optimizing PDFs for EERE and commercial search engines. PDFs are optimized by adding "metadata"—text fields that help PDFs be found in searches.

Title Fields

The title field contains the title of the PDF. This information is searched by both the EERE search engine and commercial search engines, such as Google, Yahoo, and Bing.

Use the title as it appears in the document as the PDF's title field.

When search engines list your PDF in search results, the title field will be used as the search result caption. The words you use in the title field will contribute to search engine rankings. Your PDF will rank higher in search results if the title contains the words used in the search.

Subject Fields

The subject field is used by the EERE search engine to provide a brief description of a PDF's contents in search results. The words you use in the subject field will contribute to search engine rankings. Your PDF will rank higher in search results if the subject field contains the words used in the search.

Subject fields should:

  • Contain a maximum of 200 characters, including spaces.
  • Include terms used in the PDF
  • Be simple
  • Be unique and not duplicate the subject fields of other PDFs
  • Be written as phrases instead of complete sentences. Many subject fields start with words like:
    • Provides information on...
    • Includes...
    • Information on...

If a PDF does not have a subject field, the EERE search engine will display the first few hundred characters of the file as the search result description. In this case, the search result description may be scrambled due to the fonts, columns, and other characters at the top of the PDF.

Optional Fields

Author and keyword fields are not required for PDF optimization. If you want to use author or keyword fields for your PDFs, please contact the Search Engine Specialist for tips.