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

No

While the spelling and fundamental meaning of "crianças" are identical in both dialects, there are significant differences in pronunciation, grammar, and typical usage:

• Pronunciation: In Brazilian Portuguese, the vowels are more open and clearly articulated. In Continental Portuguese, unstressed vowels (like the 'a' in crianças) are often reduced or "swallowed," making the word sound more closed and shorter.
• Grammar: The grammatical structures used alongside the word differ. Brazilians typically use the gerund (e.g., estão brincando), whereas Portuguese speakers use the preposition "a" followed by the infinitive (e.g., estão a brincar).
• Typical Usage: While "crianças" is used in both countries, it can feel slightly more formal in Portugal. In everyday conversation, a person from Portugal would more naturally use the word "miúdos" to refer to children.

Brazilian Portuguese Examples:

1. As crianças estão brincando no parque. (The children are playing in the park.)
2. Eu gosto de ver crianças felizes. (I like to see happy children.)
3. As crianças precisam comer agora. (The children need to eat now.)
4. As crianças chegaram na escola. (The children arrived at school.)
5. Onde estão as crianças? (Where are the children?)

Portuguese (Portugal) Examples:

1. Os miúdos estão a brincar no parque. (The kids are playing in the park.)
2. Eu gosto de ver miúdos felizes. (I like to see happy kids.)
3. Os miúdos precisam de comer agora. (The kids need to eat now.)
4. Os miúdos chegaram à escola. (The kids arrived at school.)
5. Onde estão os miúdos? (Where are the kids?)