CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Oct. 31, 2020	Oct. 31, 2019	Oct. 31, 2020	Oct. 31, 2019
Income Statement [Abstract]
Revenue	$ 777,196	$ 166,593	$ 1,768,883	$ 434,407
Cost of revenue	258,727	30,845	554,705	82,849
Gross profit	518,469	135,748	1,214,178	351,558
Operating expenses:
Research and development	42,582	17,573	111,705	46,410
Sales and marketing	190,157	96,048	470,886	239,741
General and administrative	93,488	23,806	227,856	63,264
Total operating expenses	326,227	137,427	810,447	349,415
Income (loss) from operations	192,242	(1,679)	403,731	2,143
Interest income and other, net	1,779	4,209	9,650	9,674
Net income before (benefit from) provision for income taxes	194,021	2,530	413,381	11,817
(Benefit from) provision for income taxes	(4,621)	319	1,675	1,851
Net income	198,642	2,211	411,706	9,966
Undistributed earnings attributable to participating securities	(202)	(4)	(531)	(2,493)
Net income attributable to common stockholders	$ 198,440	$ 2,207	$ 411,175	$ 7,473
Net income per share attributable to common stockholders:
Basic (in dollars per share)	$ 0.70	$ 0.01	$ 1.46	$ 0.03
Diluted (in dollars per share)	$ 0.66	$ 0.01	$ 1.38	$ 0.03
Weighted-average shares used in computing net income per share attributable to common stockholders:
Basic (in shares)	284,783,006	273,316,850	282,564,481	219,295,445
Diluted (in shares)	299,258,765	292,771,122	297,605,941	241,512,569