JLPT stands for the "Japanese-Language Proficiency Test". From the official JLPT website:
The Japanese-Language Proficiency Test (JLPT) has been offered by the Japan Foundation and Japan Educational Exchanges and Services (formerly Association of International Education, Japan) since 1984 as a reliable means of evaluating and certifying the Japanese proficiency of non-native speakers. At the beginning, there were approximately 7,000 examinees worldwide. In 2011, there were as many as 610,000 examinees around the globe, making JLPT the largest-scale Japanese-language test in the world.
Until 2010 there were four test levels to the JLPT and each year details of what was going to be in the test were published, such as kanji lists and vocabulary. After 2010 the tests were revised and a new level was added between the old levels 2 and 3. At the same time the JLPT organisation decided to stop publishing an official kanji list for each level in an attempt to encourage broader study of the language.
JLPT N1 is equivalent to the old JLPT level 1 |
JLPT N2 is equivalent to the old JLPT level 2 |
JLPT N3 is intended to bridge old levels 2 and 3 |
JLPT N4 is equivalent to the old JLPT level 3 |
JLPT N5 is equivalent to the old JLPT level 4 |
Because there are no longer official kanji lists, the JLPT sets in iKanji are based on a mixture of the old JLPT levels and jōyō kanji. While these should be helpful, don't take them as a authoritative list of kanji that may appear in any JLPT exam.
iKanji uses the JLPT lists compiled by Jonathan Waller