PyLaia is a Handwritten Text Recognition engine available within Transkribus. When training the HTR model, users can set several parameters on their own. The net structure of PyLaia can also be changed – a playground for people, who are familiar with machine learning. Modifications on the neural net can be done via the Github repository. Documents which have been recognised with a PyLaia-model can be searched with the Fulltext search (Solr) in Transkribus.