List of largest exoplanets

Below is a list of the largest exoplanets so far discovered, in terms of physical size, ordered by radius.

Limitations

This list of extrasolar objects may and will change over time due to diverging measurements published between scientific journals, varying methods used to examine these objects, and the notably difficult task of discovering extrasolar objects in general. These objects are not stars, and are quite small on a universal or even stellar scale. Furthermore, these objects might be brown dwarfs, sub-brown dwarfs, or not even exist at all. Because of this, this list only cites the most certain measurements to date and is prone to change.

Maximum mass limitation

Different space organisations have different maximum masses for exoplanets. The NASA Exoplanet Archive states that an object with a minimum mass lower than 30, not being a free-floating object, is qualified as an exoplanet. On the other hand, the official working definition by the International Astronomical Union allows only exoplanets with a maximum mass of 13, that are orbiting a host object at a mass ratio of less than 4% or 0.04. For the purpose of the comparison of large planets, this article includes several of those listed by NASA EA up to the maximum 30 with possible brown dwarfs among them of ≳ 13 as stated by IAU.

Classification of Sub-brown Dwarf and Rogue Objects

Sub-brown dwarfs are formed in the manner of stars, through the collapse of a gas cloud but have a planetary mass, therefore are by definition below the limiting mass for thermonuclear fusion of deuterium. However, there is no consensus amongst astronomers on whether the formation process should be taken into account when classifying an object as a planet. Free-floating sub-brown dwarfs can be observationally indistinguishable from rogue planets, which originally formed around a star and were ejected from orbit. Similarly, a sub-brown dwarf formed free-floating in a star cluster may be captured into orbit around a star, making distinguishing sub-brown dwarfs and large planets also difficult. A definition for the term "sub-brown dwarf" was put forward by the IAU Working Group on Extra-Solar Planets, which defined it as a free-floating body found in young star clusters below the lower mass cut-off of brown dwarfs.

List

The sizes are listed in units of Jupiter radii. This list is designed to include all confirmed exoplanets that are larger than 1.6 times the size of Jupiter. Some well-known exoplanets that are smaller than and are gas giants have been included for the sake of comparison.
For candidate exoplanets, either those with uncertain radii that could be below or above the adopted cut-off of 1.6 or those unconfirmed, disputed or missing either mass or yet a radius determination, see the [|list of exoplanets with uncertain radii] and [|list of unconfirmed exoplanets], respectively.
For a chronological sequence of the largest exoplanets discovered see the chronological list of largest exoplanets.
Note: Due to Jupiter being an oblate spheroid, this article uses equatorial Jupiter radius for the constant measure defined by the International Astronomical Union.

	Probably brown dwarfs
	Probably sub-brown dwarfs
?	System status uncertain
!	Uncertain system age/mass status, while probably brown dwarfs
↑	Planetary status uncertain
←	Probably exoplanets
→	Planets with grazing transit, hindering radius determination
	Notable non-exoplanets reported for reference
–	Theoretical planet size restrictions

Candidates for largest exoplanets

Exoplanets with uncertain radii

This list contains planets with uncertain radii that could be below or above the adopted cut-off of 1.6, depending on the estimate, and those with theoretical estimated radius.

	Probably brown dwarfs
	Probably sub-brown dwarfs
←	Probably planets
→	Planets with grazing transit, hindering radius determination

Illustration	Name '	Radius	Key	Mass	Notes
	TOI-1408 b	2.23 ± 0.36, 2.4 ± 0.5, > 1, 1.5,	→	1.86 ± 0.02	A large radius of has been derived from transit photometry, but this value is likely inaccurate due to the grazing transit of TOI-1408 b; it transits only part of the star's surface, thus hindering a precise measurement of planet-to-star size ratio. The study revealed a clear transit timing variations signal for TOI-1408 b, discovering super-Neptune TOI-1408 c which orbits closer to TOI-1408, and claims that their photodynamical modeling could constrain TOI-1408 b's radius more reliably, which needs to be confirmed.
	WASP-78b	1.59 ± 0.101.93 ± 0.45	←	0.89 ± 0.08	This planet has likely undergone in the past a migration from the initial highly eccentric orbit. Previous radii include:1.70 ± 0.04
	Pollera '	1.5795 ± 0.00482.09 ± 0.14	←	0.835 ± 0.077	This planet is orbiting the host star at nearly-polar orbit with respect to star's equatorial plane, inclination being equal to −95.2°. Previous radii include: 1.704 . Older masses include: 0.850 .
	AB Pictoris b '	1.57 ± 0.07, 1.4 – 2.2	←	10 ± 1	mass estimates of to, its mass is now estimated to be, with an age of million years.
	TOI-2193 Ab	> 1.55	→		Grazing planet, a large reported radius of is unreliable. Whether it is larger than is unknown.
	XO-6b '	; 1.421.93	←	4.47 ± 0.12	A very puffy Hot Jupiter. Large size needs confirmation due to size discrepancy.
	HIP 65Ab '	< 1.5	→	3.213 ± 0.078	Grazing planet.
	GSC 06214-00210 b	2.0, 1.91 ± 0.07	*	21 ± 6 15.5 ± 0.5	Has a circumsubstellar disk found by polarimetry.
	Beta Pictoris b '	1.46 ± 0.01	←		First exoplanet to have its rotation rate measured and fastest-spinning planet discovered at the equator speed of or. Also second planetary system to have the exoplanet's orbital motion confirmed. Beta Pictoris b is suspected to have an exomoon due to the former's predicted obliquity misalignment.
	HD 135344 Ab '	1.45	←	~ 10	Youngest directly imaged planet that has fully formed and orbits on Solar System scale. This planet formed in the vicinity of the snowline and later migrated to current position during its formation phase. Part of binary system HD 135344.
	TOI-3540 b	> 1.44	→	1.18 ± 0.14	Grazing planet, a large reported radius of is unreliable. Whether it is larger than is unknown.
	HD 143811 b		←	6.1	First directly imaged planet discovered orbiting near around the binary stars. The closeness suggests that HD 143811 b almost certainly formed around the stars, rather than being a captured rogue planet, or one flung far from its original location. Some news outlets compare this to Tatooine, a fiction planet that orbits near to the binary stars Tatoo I and Tatoo II.
	HD 106906 b	1.30 ± 0.06; 1.54		11 ± 2	This planet orbits around HD 106906 at the separation of 738 AU, a distance much larger than what is possible for a planet formed within a protoplanetary disk. Observations made by the Hubble Space Telescope strengthened the case for the planet having an unusual orbit that perturbed it from its host star's debris disk causing NASA and several news outlets to compare it to the hypothetical Planet Nine. It was later found that its carbon-to-oxygen ratio is similar to the stellar association it is located in, suggesting that HD 106906 b could have been captured into the system as a planetary-mass free-floating object. This does not rule out formation in a star-like manner.
	Nu Octantis Ab '	1.19 >1.6	←	2.19 ± 0.11	Has the tightest orbit around a star in a binary star system with the ratio of semi-major axis of binary star orbit to that of a planet orbiting one of the stars of 2.06, the smallest ratio of such planets. The formation and long-term stability of a planet on such a tight orbit and retrograde orbit relative to the binary's motion are challenging, but with the secondary being a white dwarf that lost most part of its mass during the evolution to a red giant and then to a white dwarf, both can be explained with either the instability of a former circumbinary planetary system that lead one of the planets to migrate inwards or by planetary formation by a second-generation protoplanetary disk that emerged from death of the white dwarf's progenitor. In the latter scenario, the radius is not yet excluded to be more than. The lower radius value is an estimate.
	GSC 08047-00232 B	1.17 – 1.85	*	25 ± 10	Third young brown dwarf companion to the host star among young, nearby associations.