Enabling detectors

Out of the box, thumbor does not enable any feature or facial detection. Enabling it is pretty easy, though.

This documentation assumes you have OpenCV installed. It is a requirement if you want to use thumbor’s Available detectors.


In order to tell thumbor what detectors it should run in the original image, you must add them to your thumbor.conf file in the following key:


The above configuration tells thumbor that it should run both the facial detection and the feature detection. These are mutually exclusive, meaning that if a face is detected, the feature detector won’t be run.

Using it

After restarting thumbor, it should be as easy as adding a /smart option to your URLs, like:


Lazy Detection

Facial detection can be pretty expensive for thumbor, so it is not advisable to do it synchronously. Please refer to the Lazy Detection page for instructions on using it.

Available Detectors

A list of available detectors can be found at Available detectors.