Thousands of students flooded the streets of London Wednesday to demand free higher education, chanting as they marched shoulder-to-shoulder and hoisted signs in the air calling for "Grants, Not Debt." In the largest such protest since 2010, the demonstrators were hoping to persuade lawmakers to eliminate tuition, fix the student debt crisis and reverse the recently announced plan to swap education grants for loans, the Telegraph reported.

The rally came about a week after a group of young protesters in South Africa blocked access to college campuses and stormed Parliament to fight tuition hikes. And the idea of free -- or, at least, cheap -- college wasn't confined to the Eastern Hemisphere: In the United States, Democratic presidential candidates Hillary Clinton and Bernie Sanders were pushing for debt-free tuition options for Americans after high school.

All this discussion seems to point to a growing international movement for more affordable education. But some countries have already slashed tuition, fees and other costs associated with college. Here's what residents pay for postsecondary education in places around the world, from high to low:

In the U.S., the average annual tuition, fees, room and board at four-year institutions totaled $23,872, according to the National Center for Education Statistics' most recent data. About 70 percent of students graduated in 2014 with debt, and their loans averaged about $28,950, according to the Institute for College Access and Success.

For residents of the European Union, most of England's universities can't charge more than £9,000, or about $13,800, in annual tuition until the 2017-2018 school year. The cost of living is about £12,000, or $18,500, but many degrees only take three years, according to the QS World University Rankings. Students' typical debt could reach about £40,000, or $61,500, in coming years, BBC News reported.

Germany announced in 2014 that it would eliminate tuition at its universities. Although school is cheap, the cost of living hovers around €8,700, or $9,445, according to QS. Similarly, Brazil's universities don't typically charge tuition, but they do require registration fees. 

But free college doesn't always equal less debt: In tuition-free Sweden in 2013, the average student owed 124,000 kr, or about $19,000, Quartz reported.

Chinese students' annual tuition is usually between $3,300 and $9,900, according to China's University and College Admission System, and the cost of living in cities can exceed $700. noted that "student loans are relatively unheard of in China."

In India's Institute of Technology system, tuition averages around 40,000 Rs, or $1,400, a year. Student loan data was unclear, though urban households had an average of 85,00 Rs, or $1,300, in 2012.

Students in Denmark, which joins countries like Finland and Iceland in offering free higher education to locals, actually get a stipend while in school. "Danish universities have one of the highest graduation rates among all Organization for Economic Cooperation and Development (OECD) member countries, and its citizens are practically free of student debt," the Washington Post wrote earlier this year, adding that some officials worried this was contributing to high unemployment rates.