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

Yes

The difference between the use of "leitor" in Brazilian Portuguese and Continental Portuguese is purely phonetic. There are no differences in meaning, spelling, grammar, or fundamental usage. In Brazilian Portuguese, the pronunciation tends to be more open, with vowels being clearly articulated. In Continental Portuguese, unstressed vowels are often reduced or shortened, which can make the word sound more "closed" or clipped to a Brazilian ear.

Brazilian Portuguese Examples

1. Eu sou um leitor de histórias de terror. (I am a reader of horror stories.)
2. O leitor pode encontrar o link logo abaixo. (The reader can find the link right below.)
3. Estamos buscando novos leitores para o nosso blog. (We are looking for new readers for our blog.)
4. Ele é um leitor muito dedicado e atento. (He is a very dedicated and attentive reader.)
5. Para o letor iniciante, eu recomendo este autor. (For the beginner reader, I recommend this author.)

Continental Portuguese Examples

1. Sou um leitor assíduo de literatura clássica. (I am an assiduous reader of classical literature.)
2. O leitor deve consultar o índice para encontrar o capítulo. (The reader must consult the index to find the chapter.)
3. Esta revista foi escrita para o leitor moderno. (This magazine was written for the modern reader.)
4. Um leitor atento notará a importância deste detalhe. (An attentive reader will notice the importance of this detail.)
5. Dirigimo-nos ao leitor com esta nova edição. (We address the reader with this new edition.)