DebugR is a free Chrome add-on developed by Bob Fanger. It falls under the category of Browsers and is specifically categorized as an Add-ons & Tools subcategory.

DebugR allows users to receive debugging information alongside XMLHttpRequests. The server code, which can be written in any language, includes a condition to send headers only when DebugR is enabled. The headers contain messages that are encoded using base64. Users can append unique labels to send multiple messages.

On the client side, DebugR can be used via JavaScript. Users can add an event listener to receive the debugging information and log it in the console. Additionally, by signaling the extension that the event listener is active, users can enable DebugR for their debugging needs.

For a more convenient debugging experience, DebugR also provides a helper called debugr.js. By including this helper script and using its functions, users can easily log the debugging messages and details in the console.