.htaccess Pro: Rewrite Rules Under the Microscope

Field notes

The page describes a local simulation pipeline rather than a server connection: users provide request details, the engine evaluates rules and conditions, and the trace ends with a concrete routing verdict. It can jump from a trace line to the corresponding source line and flags issues such as missing RewriteEngine On, orphaned conditions, invalid flags, and non-redirect R= codes. The engine is presented as the same six source files used by the plugin, with an MIT-licensed repository and npm command-line version.