As we see a ramping-up of online teacher professional learning and development (PLD) offerings, it is becoming increasingly imperative to consider the complexity and nuances of what constitutes effective online teacher PLD, and to be able to plan and evaluate it. There is a need for PLD to be 'genuinely effective', but while descriptions of effective teacher PLD abound, effective online teacher PLD is not as clearly articulated. We analyse characterisations of effective PLD and the extent to which they apply to online contexts. We argue that for online PLD to be genuinely effective--relevant, collaborative and future focused--attention must be paid to practice architectures that hold online PLD in place, to technological demands and to how evidence regarding PLD efficacy is generated and collected. To this end, we propose a heuristic framework for planning and evaluating online PLD.