Precompiled binaries for each release are available from » PECL for a variety of combinations of versions, thread safety, and VC libraries. Extract the archive and put librdkafka.dll in the root PHP directory (same level as php.exe) and the php_rdkafka.dll file in your PHP extension directory ("ext" by default).
Note:
Each precompiled binary works only for a specific PHP build. Please make sure to download the right one after opening the DLL link on » PECL.
Add the following line to your php.ini file:
extension=php_rdkafka.dll