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

Yes

The word "sites" is identical in meaning, spelling, and grammatical function in both Brazilian and Continental Portuguese. The only difference is pronunciation. In Brazilian Portuguese, the pronunciation is typically more open, often approximating the English diphthong (/saɪts/). In Continental Portuguese, the pronunciation is much more "closed" and "clipped," with a heavily reduced vowel sound, which is a standard feature of the European Portuguese phonetic system.

Brazilian Portuguese

1. Eu visitei vários sites de notícias hoje. (I visited several news sites today.)
2. Esse site está fora do ar. (This site is down.)
3. Você já viu esses sites de compras? (Have you seen these shopping sites?)
4. Eu preciso criar alguns sites novos. (I need to create some new sites.)
5. Esse site é muito legal. (This site is very cool.)

Continental Portuguese

1. Eu visitei vários sites de notícias hoje. (I visited several news sites today.)
2. Este site está em baixo. (This site is down.)
3. Já viste estes sites de compras? (Have you seen these shopping sites?)
4. Tenho de criar alguns sites novos. (I have to create some new sites.)
5. Este site é muito fixe. (This site is very cool.)