At face value the ENTJ and the INTJ are very similar. Both types have a love of complexity, both are intensely logical and both have a relentless, restless drive to change things, make them better and for closure. However the E vs I dichotomy makes such a difference and means they tend to inhabit different worlds.
The ENTJ inhabits the external world of people and situations, drawing energy from interactions and will love being loud, visible and will have (extremely strong) opinions on almost every subject.
The INTJ inhabits the internal world, detached and independent of thought and action, and they tend to keep it all inside until they are ready. Their need for privacy and independence means they will be quite reclusive, working behind the scenes to reflect, build and solve problems. The ENTJ is far more ‘out there’ loving the verbal sparring and robust debate and keen to make their point. Don’t ask the views of an ENTJ unless you are prepared for a bone-jarring honesty.
Strangely enough the INTJ shares that ‘tell it like it is’ character trait but will be less interested in expressing a view, unless it is on a subject that is of great interest to them, or is their latest plan, in which case the INTJ will happily wax lyrical. But once the subject becomes more mundane the INTJ will gladly retreat to their own world of ideas, possibilities and complexity: think Margaret Thatcher vs Mark Zuckerberg, both strident, both very strong willed, both relentlessly following what they believed in, both loving the new, the untried, the untested. But one was totally exposed and ‘out there’ so everyone knew where they stood and one is far more deep and analytical, waiting for the right moment to bring their ideas forth, only once they are perfectly formed.
Check out our full comparison of ENTJ vs INTJ characteristics.