* The specific Brazilian institution: Different universities and employers in Brazil have varying acceptance policies for foreign degrees. Some may readily accept accredited US online programs, while others may prefer or require degrees earned through traditional on-campus study. There's no single, universal answer.
* Accreditation of the US university: The US university granting the degree must be regionally accredited. Brazilian institutions are more likely to accept degrees from regionally accredited universities than nationally accredited ones (or unaccredited institutions). You need to check the accreditation status of the specific university offering the online program.
* The program's rigor and reputation: Even with accreditation, a program's reputation and the perceived rigor of its curriculum will influence acceptance. A well-regarded program from a prestigious university is more likely to be accepted than one from a lesser-known institution.
* The specific requirements of the position or program: If you're applying for a job or further education in Brazil, the specific requirements of that institution or employer will dictate whether the online Master's degree is sufficient.
In short: You must contact the specific Brazilian university, employer, or licensing body to determine their acceptance of an online Master's degree from a particular US university. Simply knowing it's a US online degree isn't enough; you must provide details about the university and its accreditation. They may require you to submit your transcripts and other documentation for evaluation.