Disclosure: MantraBrain is associated with MatrixAddons, the maker of Document Engine. We explain where the free plugin works well and where the paid add-on is needed.
If your website hosts dozens of PDF manuals, reports or policies, a long list of download links quickly becomes frustrating. A searchable PDF library lets readers narrow the collection by title, category, year and file type, preview files and download what they need.
Understand the three kinds of PDF search
Library search finds documents using their WordPress document information. Viewer search finds words inside one PDF that a visitor has opened. Full-text library search searches the contents of many uploaded files. These are different capabilities, so check which one your project needs before selecting a plugin.
1. Plan the structure
Write down the categories your readers expect, such as Reports, Policies, Guides and Forms. Decide whether year, department or document type should be a filter. Use descriptive titles and short summaries; this helps both visitors and the free library search.
2. Install and activate Document Engine
From Plugins → Add New Plugin, install Document Engine. The free plugin provides a document content type, a Document Library block, table/grid/folder layouts and instant filters.
3. Upload and categorize PDFs
Open Documents → Add New, title the PDF, select its file, add a description and choose categories. Publish the document. Repeat for a handful of files before creating the public library. You can also convert existing Media Library files into documents in bulk from the Media Library list view.
4. Add the library block
Create a page and insert Document Library. Choose a table for policies and reports, a grid for visual guides, or folders for category-first navigation. Enable search and filters for categories, file type and year. If you prefer a shortcode, use [document_engine_library file_types="pdf" filters="category,year,sort"].
5. Add PDF previews
The included self-hosted PDF.js viewer lets readers open PDFs without relying on Google Docs. Its tools include in-document search, thumbnails and an outline when available in the file. You can configure a preview popup in the library settings. Test both desktop and mobile display.
6. Add file-content search with Pro
If users must search a phrase across hundreds of PDF documents, upgrade to Document Engine Pro. Pro indexes supported file contents, including PDFs and common office formats, for library and site search. Note that image-only scanned PDFs may require OCR before their text can be searched; check the source file rather than assuming every scan is searchable.
7. Improve the search experience
- Use one consistent naming format for documents.
- Include dates and versions where readers need them.
- Keep categories short and meaningful.
- Remove or archive obsolete files.
- Test common queries with a colleague unfamiliar with the library.
Free versus Pro: which do you need?
Choose the free plugin for public PDF collections with metadata search, filters and previews. Choose Pro for full-text search across files, private access, audit logs or controlled sharing. Neither option replaces the need to create accessible, properly tagged PDF files.
FAQ
Does WordPress search inside PDF files by default?
WordPress does not provide a complete, searchable PDF document library out of the box. A dedicated plugin can add document indexing and a search interface.
Is the PDF viewer hosted by Google?
No. Document Engine uses PDF.js on your own site.
Can I restrict some PDFs?
Yes, with Document Engine Pro’s access controls and protected storage.
Copy-and-paste PDF-only library example
Place this in a Shortcode block to display only PDFs, with category and year filters:
[document_engine_library file_types="pdf" filters="category,year,sort" search="yes" per_page="20"]Want to filter by multiple categories at once? Set multi_filters="yes". Document Engine uses shareable URL parameters for filters, so readers can bookmark a filtered library view. These are documented plugin options, not custom code.
How to test whether full-text search is working
- Upload a PDF containing a distinctive phrase in selectable text.
- Give the document a title and description that do not include that phrase.
- Search the library for the phrase. In the free version, metadata search alone should not be expected to find it.
- With Pro’s file-content indexing configured, repeat the test and check whether the PDF appears.
- Repeat with a scanned PDF. If it contains only an image, OCR may be needed first.
For search inside an individual opened PDF, use the self-hosted PDF.js viewer instead. That does not imply indexing across the whole library.
Try it: Get Document Engine free or explore Document Engine Pro. For the exact settings, consult the official setup documentation.