Is the word janela the same in Brazilian and European Portuguese?

Yes

The word "janela" is identical in meaning, spelling, and grammatical gender in both Brazilian and European Portuguese. The only differences are phonetic. In Brazil, the pronunciation tends to be more "open," with clearly articulated vowels and a more melodic, syllable-timed rhythm. In Portugal, the pronunciation is more "closed," with significant reduction or even the near-disappearance of unstressed vowels, creating a more stress-timed rhythm.

Brazilian Portuguese Examples

1. Abra a janela, por favor. (Open the window, please.)
2. Eu gosto de olhar pela janela. (I like to look through the window.)
3. A janela está aberta. (The window is open.)
4. Estão limpando a janela agora. (They are cleaning the window now.)
5. A janela do meu quarto é muito grande. (The window in my bedroom is very big.)

European Portuguese Examples

1. Abre a janela, por favor. (Open the window, please.)
2. Eu gosto de olhar pela janela. (I like to look through the window.)
3. A janela está aberta. (The window is open.)
4. Estão a limpar a janela agora. (They are cleaning the window now.)
5. A janela do meu quarto é muito grande. (The window in my room is very big.)