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

No. While the core meaning and spelling are identical, there are differences in typical usage, grammatical context, and pronunciation.

In Brazilian Portuguese, "achar" is the standard, everyday verb used for both expressing an opinion and for the act of finding or locating a lost object. In Continental Portuguese, while "achar" is used for opinions, "encontrar" is much more natural and frequent when referring to the act of finding or encountering something. Furthermore, the grammatical environment changes because Portuguese speakers in Portugal use the second-person (tu) more naturally, whereas Brazilians favor the third-person (você). Finally, there is a phonetic difference, as vowels are typically more closed and reduced in Portugal compared to the more open vowels in Brazil.

Brazilian Portuguese Examples

1. Eu acho que ele vai chegar tarde. (I think he will arrive late.)
2. Você achou o seu celular? (Did you find your cell phone?)
3. Eu achei que você estava triste. (I thought you were sad.)
4. O que você acha desse restaurante? (What do you think of that restaurant?)
5. Não achei nada na mochila. (I didn't find anything in the backpack.)

Continental Portuguese Examples

1. Eu acho que ele vai chegar tarde. (I think he will arrive late.)
2. Tu encontraste o teu telemóvel? (Did you find your mobile phone?)
3. Achei que estavas triste. (I thought you were sad.)
4. O que achas desse restaurante? (What do you think of that restaurant?)
5. Não encontrei nada na mochila. (I didn't find anything in the backpack.)