What is included in Foxit PDF IFilter?

PDF Text Indexing – Extracts document text for Microsoft search engines.
Metadata Indexing – Covers titles, authors, keywords, annotations and attachments.
Server Search Integration – Runs under SharePoint, SQL Server and Exchange.
Multi-Core Crawling – Thread-safe indexing across several server CPU cores.
Core Capacity – Twelve indexing languages, including Chinese, Japanese and Korean.
Important – No OCR engine; scanned image-only PDFs stay unsearchable.

What are the main benefits of Foxit PDF IFilter?

Foxit PDF IFilter is a plug-in for Microsoft's IFilter interface that lets Windows and Microsoft server search products read inside PDF files instead of only reading file names. It has no window and no menus: it registers a DLL, and the search engine calls it during every crawl.

One Search Index – PDFs appear beside Office files in results.
Faster Crawls – Multi-threaded design shortens full crawls on busy servers.
Deep Field Coverage – Form data and annotations become searchable too.
Invisible To Users – No interface, no client rollout, registry-only configuration.
Mixed-Language Archives – Handles CJK, Arabic and Hebrew document sets.
Server-Wide Reach – Server edition covers Exchange, SQL and SharePoint.

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What does Foxit PDF IFilter do?

It extracts text, document properties, bookmarks, form fields, annotations and file attachments from PDF documents and hands the result back to a Microsoft search engine so the content can be indexed. Windows and SharePoint index Office formats natively but cannot read PDF internals without a registered IFilter, so PDFs otherwise return matches only on file name and basic properties. Foxit PDF IFilter supports the PDF 1.7 specification and installs as a DLL (pdffilt.dll) with a fixed CLSID that the crawler looks up in the registry. In practice this is what turns a shared folder of 20,000 supplier invoices into something a colleague can search by invoice number.

Which search engines and server products does it support?

The Server edition works with Windows Indexing Service, SharePoint Portal Server and MOSS, Windows SharePoint Services, Internet Information Server, Site Server, Microsoft SQL Server full-text search, and Microsoft Exchange Server. For SQL Server the filter is registered with the sp_fulltext_service commands and PDFs are stored as varbinary(MAX) column data, which means scanned-in contracts held inside a database row can be found with a CONTAINS query. On Exchange, it indexes PDF email attachments so a mailbox search returns the message that carried the file. The product is Windows-only; there is no macOS or Linux build, and it must be installed on every server that runs an active crawl component.

What is the difference between the Desktop and Server versions?

The Desktop edition indexes PDFs for local Windows desktop search only, while the Server edition adds the server search environments and the licensing that permits use on a server. Foxit's own Desktop manual points users who need both environments to the Server version, so a Desktop copy installed on a SharePoint crawl server is the wrong edition rather than a cheaper one. If your goal is making PDFs findable inside SharePoint, SQL Server or Exchange, only the Server edition applies.

Does Foxit PDF IFilter run OCR on scanned documents?

No. Foxit PDF IFilter reads text that already exists in the PDF and contains no text-recognition engine, so an image-only scan produces nothing for the crawler to index. Foxit places OCR in Foxit PDF Editor, where Convert > Recognize Text writes a searchable text layer over the scan; once that layer exists, the IFilter can index it normally. This matters most for archives fed by a document scanner, where the files look identical to real text PDFs in Explorer but return zero search hits. Neither edition adds editing, redaction or legally binding e-signatures either — the product only feeds a search index.

Why do bookmarks not appear in my PDF search results?

Because Foxit PDF IFilter filters out bookmarks by default. The behaviour is controlled by the FilterBookmarks value under HKEY_LOCAL_MACHINE\SOFTWARE\Foxit Software\Foxit PDF IFilter, alongside FilterAnnotation and FilterAttachFile, and a value of 0 means the content is kept rather than discarded. After changing any of these, the crawl service has to be restarted and the affected content re-crawled before the change shows up in results. A LogLevel value from 0 to 3 and a LogFilePath entry are available in the same key, which is the practical way to find out why a specific file produced no text.

What should users check before choosing Foxit PDF IFilter?

Check the product lifecycle first: Foxit set End-of-Sales for PDF IFilter on 22 August 2025 and End-of-Life on 14 July 2026, after which no updates or support are provided, though existing licences continue to work. That makes it a fit for stable, frozen environments such as an older SharePoint or SQL Server farm that still needs PDF crawling, and a poor fit for a platform you expect to upgrade repeatedly. Also confirm the architecture, since the installer ships as separate 32-bit and 64-bit packs and the wrong pack simply will not register. Finally, verify that no other PDF IFilter is registered on the same crawl server, because a competing filter or a Microsoft update can overwrite the .pdf CLSID entry and silently take over indexing.

Frequently asked questions about Foxit PDF IFilter

Where should Foxit PDF IFilter be installed?

On every indexing or crawling server, meaning any machine running an active Search Service component. In a SharePoint farm it goes on the crawl server, not on the web front ends or on user workstations.

Is there a file size limit for indexed PDFs?

Foxit PDF IFilter itself applies no size restriction to PDFs. Any cap you hit comes from Windows Search, via the MaxDownloadSize and MaxGrowFactor values under the Gathering Manager registry key, and the search service must be restarted for a change there to take effect.

Does Foxit PDF IFilter have a user interface?

No. After installation it appears in the Control Panel program list but opens no window at all. All behaviour is set through five registry values, and the only visible confirmation of correct operation is that PDF content starts appearing in search results.

Does it work with SharePoint 2013 and SharePoint 2016?

Yes, provided hotfix KB2883000 is installed. Both versions ship a built-in PDF handler, so you must switch the farm to a third-party filter with Set-SPEnterpriseSearchFileFormatState, then run iisreset and restart the search host controller and the osearch15 or osearch16 service.