Net Income (Loss) Per Share - Summary of Basic and Diluted Net Income (Loss) Per Share Attributable to Common Stockholders (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Numerator:
Net income (loss) attributable to AppLovin	$ (10,521)	$ 4,664
Income attributable to convertible preferred stock		(1,545)
Income attributable to options exercises by promissory notes		(82)
Income attributable to unvested early exercised options		0
Income attributable to unvested RSA's		(50)
Net income (loss) attributable to common stock—Basic	$ (10,521)	$ 2,987
Denominator:
Weighted-average shares used in computing net income (loss) per share—Basic	222,408,568	210,898,346
Net income (loss) per share attributable to common stock—Basic	$ (0.05)	$ 0.01
Numerator:
Net income (loss) attributable to AppLovin	$ (10,521)	$ 4,664
Income attributable to convertible preferred stock		(1,530)
Income attributable to options exercises by promissory notes		(81)
Income attributable to unvested early exercised options		0
Income attributable to unvested RSA's		(49)
Net income (loss) attributable to common stock—Diluted	$ (10,521)	$ 3,004
Denominator:
Weighted-average shares used in computing net income (loss) per share—Basic	222,408,568	210,898,346
Weighted-average dilutive stock options		3,155,094
Weighted-average shares used in computing net income (loss) per share—Diluted	222,408,568	214,053,440
Net income (loss) per share attributable to common stock—Diluted	$ (0.05)	$ 0.01