Gas giant
The smallest known extrasolar planet that is likely a "gas planet" is Kepler-138d, which has the same mass as Earth but is 60% larger and therefore has a density that indicates a thick gas envelope.
List of exoplanets detected by microlensing
The most massive planet detected by microlensing is MOA-bin-1b, which masses ; the least massive is MOA-2007-BLG-192Lb, which masses or . The widest separation between a planet and a star is MOA-bin-1b, which is 8.3 AU; the shortest separation is MOA-2007-BLG-192Lb, which is 0.66 AU.