Planejar vs. planear
The Portuguese verbs planejar and planear share the exact same meaning, which is to create a plan, organize, or intend to do something. The fundamental difference between them is geographical. Planejar is the standard form used in Brazilian Portuguese, while planear is the standard form used in European Portuguese (Portugal) and other Portuguese-speaking countries in Africa.
Planejar
A2This is the Brazilian Portuguese variation of the verb to plan. It is used when identifying the steps needed to achieve a goal or simply intending to do an activity.
Nós precisamos planejar nossas próximas férias.
(We need to plan our next vacation.)
A empresa está planejando lançar um novo produto.
(The company is planning to launch a new product.)
Você costuma planejar seu dia na noite anterior?
(Do you usually plan your day the night before?)
É difícil planejar o futuro em tempos incertos.
(It is difficult to plan the future in uncertain times.)
O arquiteto começou a planejar a reforma da casa.
(The architect started to plan the house renovation.)
Planear
A2This is the European Portuguese variation of the verb to plan. It carries the exact same definition as the Brazilian version but involves a slightly different spelling and pronunciation.
Estou a planear uma viagem ao Algarve.
(I am planning a trip to the Algarve.)
O governo vai planear a construção de uma nova ponte.
(The government will plan the construction of a new bridge.)
Não vale a pena planear tanto se tudo pode mudar.
(It is not worth planning so much if everything can change.)
Eles devem planear o orçamento com cuidado.
(They must plan the budget carefully.)
Conseguimos planear o evento em apenas dois dias.
(We managed to plan the event in just two days.)
Summary
In short, there is no semantic difference between planejar and planear. Your choice should depend entirely on your audience. Use planejar if you are communicating in Brazil, and use planear if you are in Portugal.