If in doubt as to which version to download, read this.

Available Downloads

Requires MySQLi and MySQLnd extensions
PHP 7.0 or greater
MySQL 5.5.3+ or MariaDB

Requires MySQLi and MySQLnd extensions
PHP 7.0 or greater
MySQL 5.5.3+ or MariaDB

Requirements_check.php is a definitive check to help determine if Sphider or SphiderLite will work on your system.
Be sure to check this blog post before requesting the PDO version.

Windows port of Catdoc
Binaries and source code
Converts .doc, .ppt, & .xls files to text

Which version should I download?

The version downloaded depends on your needs. SphiderLite is most like the original Sphider, while Sphider has added capabilities. It can index images and RSS feeds. Both have MySQLnd requirements that not all hosts provide. The PDO version is then needed. Older PHP installations may need something not using prepared statements. Read on for more details.

Sphider 5.5.0 the most robust version. It can index not just text content, but can also index images. There is also an RSS feed indexing capability. This version DOES require both the MySQLi and MySQLnd extensions to PHP. Some hosting providers have DISABLED the MySQLnd extension, particularly for clients using shared hosting. Check with your system administrator or hosting provider to assure that the MySQLnd extension is available.¹ The installed database used is either MySQL 5.5.3+ or MariaDB. This version can handle multibyte strings. The PHP mbstring extension is required.

SphiderLite 2.6.0 has the same requirements as Sphider 5.5.0. For normal site indexing, it is the same as Sphider 5.5.0. However, SphiderLite has no RSS or image indexing/search capabilities, nor ability to produce a links report. 2.6.0 requires PHP 7.0.0 or greater!

Pandoc required for indexing docx and odt files

Pandoc is pre-installed on many platforms, but it is best to check for sure. If it is not on your platform, it is easy to get.

Pandoc is a free document converter. Sphider uses it to index docx and odt files. The latest release of Pandoc is available for WIndows, MAC, and both Debian and RPM based Linux systems.

Optional utility for Windows

Catdoc is an optional, third party add-on for Windows users who wish to be able to convert *.doc, *.ppt, and *.xls files to text. On Linux systems, check with your system administrtor or hosting provider to see if this feature is available. It is NOT required for the conversion of pdf files to text.

Catdoc is a port to Windows of catdoc, catppt, and xls2csv utilities found in Linux. This is a third-party compilation containing Windows binaries as well as source code. We have done some basic testing from a Windows command prompt. We used a Windows 7 x64 based machine. First, a directory C:\bin\linux2winports was created. From the zip file (provided as a download) we extracted the three exe files and the charsets directory to the directory created. We got 2 errors complaining of the extraction failing to set timestamps on two of the files. Ignore the warnings. The extracted binaries are win32 (for x86), but they worked in our x64 environment. We did not try any of the options but simply a command like "catdoc somefile.doc", "catppt someppt.ppt", and "xls2csv spreadsheet.xls". We received expected outputs, so the port does work, at least on a basic level.

The recommendations are to use the pre-compiled binaries provided, but if you have the know-how to make your own binaries, you are free to do so. The binaries are win32, but it may be possible to use the source to make x64 binaries. We don't know, haven't tried. This package is provided as-is.

NOTE 1: Download, extract, and run this script.
This will tell if the latest Sphider will work for you. This is a definitive check.

The above method is definitive. You can also create a script:
Upload this to your server and run it. If you get results like this(in the"mysqlnd" section, last line, "API Extensions", should contain at least "mysqli") you SHOULD be good, but SOME hosting companies may STILL block actual access to MySQLnd for users on shared hosting plans. If there is no "mysqlnd" section, or "API Extensions" shows "no value", mysqlnd is not enabled.
PHP Info screen shot

CPanel settings to enable mysqlnd:

Cpanel settings
If you find that mysqlnd is not enabled, you may still be able to enable it. Here is a blog post which may help.