The Japanese-Language Proficiency Test , or JLPT, is a standardized criterion-referenced test to evaluate and certify Japanese language proficiency for non-native speakers, covering language knowledge, reading ability, and listening ability. The JLPT was first held in 1984 in response to growing demand for standardized Japanese language certification. Initially 7,000 people took the test.

The test is held twice a year in Japan and selected countries (on the first Sunday of July and December), and once a year in other regions (on the first Sunday of December). 

The JLPT consists of five levels. Until 2009, the test had four levels, with 4 being the lowest and 1 being the highest level of certification. JLPT certificates do not expire or become invalid over time.

In 2004, the JLPT was offered in 40 countries, including Japan. Of the 302,198 examinees in that year, 47% (around 140,000) were certified for their respective level. The number of candidates continued to rise to 559,056 in 2008, while the percentage of candidates certified has fallen below 36%.

In 2009, when a revised system was introduced in which two exams are held each year in East Asia, a total of 768,114 people took the exam. In 2010, 610,000 people took the test.

According to en.wikipedia