Lack of teacher training on Internet use and slow connections to the Web are among the problems found in Brazilian schools, the Brazilian Internet Committee, or CGIB, said in a report.
Two-thirds of teachers surveyed described themselves as "self-taught" when it came to using the Internet, while 57 percent acknowledged completing a computer course, the CGIB said.
Among teachers who took a course, 74 percent paid for it themselves.
Another hindrance to the use of the Internet in schools was the slow speed of connections, limiting access in rural areas, mostly because of simultaneous use at a single spot, the report said.
By 2014, 41 percent of public schools linked to the Internet had a 2 MBps connection, compared to 50 percent a year earlier.
Last year, only 21 percent of private schools had a 2 MBps connection.
Among public schools with computers, 93 percent have access to the Internet, compared to 97 percent of private schools.
The study found that 64 percent of teachers preferred using their personal cell phones to access the Internet at school, compared to 36 percent in 2013.
Some 83 percent of teachers use the Internet to produce class content and 28 percent use Web tools to communicate with students.
Forty-one percent of public school students connected to the Internet from computers at school.
The report, published annually since 2010, surveyed 930 schools between September 2014 and March 2015, obtaining responses from 930 principals, 1,700 teachers and 9,532 students across Brazil.