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

No.

While the spelling and core meanings (lack of physical strength, low intensity, or low quality) are identical, there is a difference in typical usage. In Brazil, "fraco" is frequently used as slang to describe something as "lame," "uninteresting," or "not cool." In Portugal, while "fraco" can imply poor quality, a Portuguese person is much more likely to use other expressions (such as "uma seca") to convey the idea of something being "lame" or "boring." Additionally, the surrounding grammar (such as the use of possessive pronouns) differs.

Brazilian Portuguese Examples

1. Ele está muito fraco depois da gripe. (He is very weak after the flu.)
2. Esse café está muito fraco. (This coffee is very weak.)
3. O sinal do Wi-Fi está bem fraco aqui. (The Wi-Fi signal is very weak here.)
4. Essa sua desculpa é muito fraca. (That excuse of yours is very weak.)
5. Essa piada foi muito fraca. (That joke was very lame.)

Portuguese (Portugal) Examples

1. Ele está muito fraco após a gripe. (He is very weak after the flu.)
2. Este café está muito fraco. (This coffee is very weak.)
3. O sinal do Wi-Fi está muito fraco aqui. (The Wi-Fi signal is very weak here.)
4. Essa tua desculpa é muito fraca. (That excuse of yours is very weak.)
5. Essa piada foi uma seca. (That joke was boring/lame.)