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

No

While the core definition of "junto" (together, attached, or next to) is identical in both variants, the typical usage differs. In Brazilian Portuguese, "junto" is frequently used as an adverb to mean "along" or "at the same time" (e.g., "mandei junto" — I sent it along). In Continental Portuguese, this is less common; speakers prefer "em anexo" (attached) or "ao mesmo tempo" (at the same time). Additionally, Brazilians often use the construction "junto com" to express accompaniment, whereas Portuguese speakers frequently prefer the simpler "com" or the phrase "ao lado de" to denote physical proximity.

Brazilian Portuguese Examples

1. Nós estamos juntos nesta situação. (We are together in this situation.)
2. Eu mandei o arquivo junto com o e-mail. (I sent the file along with the email.)
3. A padaria fica junto ao metrô. (The bakery is next to the subway.)
4. O controle remoto está junto ao sofá. (The remote control is next to the sofa.)
5. Eles trabalamos juntos no projeto. (They work together on the project.)

Continental Portuguese Examples

1. Nós estamos juntos nesta situação. (We are together in this situation.)
2. Enviei o ficheiro em anexo ao e-mail. (I sent the file attached to the email.)
3. A padaria fica ao lado do metro. (The bakery is next to the subway.)
4. O comando está ao lado do sofá. (The remote control is next to the sofa.)
5. Eles trabalham juntos no projeto. (They work together on the project.)