Net Income (Loss) Per Share - Summary of Basic and Diluted Net Income (Loss) Per Share Attributable to Common Stockholders (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended				6 Months Ended
	Jun. 30, 2021	Mar. 31, 2021	Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2021	Jun. 30, 2020
Numerator:
Net income (loss) attributable to AppLovin	$ 14,423	$ (10,521)	$ (21,391)	$ 4,664	$ 3,902	$ (16,727)
Income attributable to convertible preferred stock	(902)		0		(731)	0
Income attributable to options exercised via promissory notes	(140)		0		(55)	0
Income attributable to unvested early exercised options	(61)		0		(12)	0
Income attributable to unvested RSA’s	(25)		0		(9)	0
Net income (loss) attributable to common stock—Basic	$ 13,295		$ (21,391)		$ 3,095	$ (16,727)
Denominator:
Weighted-average shares used in computing net income (loss) per share—Basic (in shares)	335,619,207		213,440,147		279,326,624	212,169,247
Net income (loss) per share attributable to common stock—Basic (in dollars per share)	$ 0.04		$ (0.10)		$ 0.01	$ (0.08)
Numerator:
Net income (loss) attributable to AppLovin	$ 14,423	$ (10,521)	$ (21,391)	$ 4,664	$ 3,902	$ (16,727)
Income attributable to convertible preferred stock	(859)		0		(693)	0
Income attributable to options exercised via promissory notes	(132)		0		(53)	0
Income attributable to unvested early exercised options	(59)		0		(11)	0
Income attributable to unvested RSA’s	(24)		0		(8)	0
Net income (loss) attributable to common stock—Diluted	$ 13,349		$ (21,391)		$ 3,137	$ (16,727)
Denominator:
Weighted-average shares used in computing net income (loss) per share—Basic (in shares)	335,619,207		213,440,147		279,326,624	212,169,247
Weighted-average dilutive stock options (in shares)	18,238,607		0		19,179,641	0
Weighted-average shares used in computing net income (loss) per share—Diluted (in shares)	353,857,814		213,440,147		298,506,265	212,169,247
Net income (loss) per share attributable to common stock—Diluted (in dollars per share)	$ 0.04		$ (0.10)		$ 0.01	$ (0.08)