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

Yes

The word "útil" is identical in meaning, spelling, and grammatical function in both Brazilian and European Portuguese. The only difference is in pronunciation. In most Brazilian dialects, the "t" is palatalized, meaning it sounds like the "ch" in "cheese" (e.g., ú-chi-u), and the final "l" is vocalized to an "u" sound. In Continental Portuguese, the "t" is a dental sound (the tongue touches the teeth), and the word is pronounced with a more closed, staccato rhythm.

Brazilian Portuguese Examples

1. Este livro é muito útil para a prova. (This book is very useful for the exam.)
2. Achei esse aplicativo bem útil. (I found this app very useful.)
3. É útil ter um celular sempre à mão. (It is useful to have a cell phone always at hand.)
4. Essa dica foi super útil para mim. (This tip was super useful for me.)
5. O computador é uma ferramenta útil. (The computer is a useful tool.)

European Portuguese Examples

1. Este livro é muito útil para o exame. (This book is very useful for the exam.)
2. Achei esta aplicação muito útil. (I found this application very useful.)
3. É útil ter um telemóvel sempre à mão. (It is useful to have a mobile phone always at hand.)
4. Esta dica foi bastante útil para mim. (This tip was quite useful for me.)
5. O computador é uma ferramenta útil. (The computer is a useful tool.)