Before 2010, there were only 4 levels of the JLPT, and the test agency released official vocabulary and grammar lists. One level was split in two, forming the current N2 and N3 levels. Since then, the test agency has not released vocabulary or grammar lists for either of these levels. As such, the N2 and N3 lists here are formed using things test takers remember and general estimates as to the difficulty of the material, and should not be considered entirely comprehensive. The N5, N4, and N1 material should be rather representative.
Some websites have not been updated to reflect the 2010 level changes to the JLPT. If a site only talks about levels 4 through 1, it is referring to the old test levels. See Japanese Language Proficiency Test for details.