NAT-Test
The Japanese Language NAT-TEST is an examination that measures the Japanese language ability of students who are not native Japanese speakers. The tests are separated by difficulty (five levels) and general ability is measured in three categories: Grammar/Vocabulary, Listening and Reading Comprehension. The format of the exam and the types of questions are equivalent to those that appear on the Japanese-Language Proficiency Test (JLPT).
NAT-TEST's question standards and structure are NAT-TEST is the same level as JLPT, so it is the best preparation for JLPT. JLPT does not disclose the criteria for questions, the number of vocabulary and kanji for each level, but NAT -TEST are all disclosed.