CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jul. 31, 2021	Jul. 31, 2020	Jul. 31, 2021	Jul. 31, 2020
Income Statement [Abstract]
Revenue		$ 272,198	$ 133,145	$ 501,112	$ 241,960
Cost of revenue		106,121	50,446	203,467	93,003
Gross profit		166,077	82,699	297,645	148,957
Operating expenses:
Sales and marketing		182,903	92,663	349,707	190,540
Research and development		118,087	36,533	227,883	69,811
General and administrative		65,228	31,186	125,791	62,692
Total operating expenses		366,218	160,382	703,381	323,043
Operating loss		(200,141)	(77,683)	(405,736)	(174,086)
Interest income		2,190	1,689	4,802	4,137
Other income (expense), net		8,746	(1,109)	8,258	(1,042)
Loss before income taxes		(189,205)	(77,103)	(392,676)	(170,991)
Provision for income taxes		514	531	263	287
Net loss		$ (189,719)	$ (77,634)	$ (392,939)	$ (171,278)
Net loss per share attributable to Class A and Class B common stockholders - basic (in dollars per share)	[1]	$ (0.64)	$ (1.31)	$ (1.33)	$ (3.01)
Net loss per share attributable to Class A and Class B common stockholders - diluted (in dollars per share)	[1]	$ (0.64)	$ (1.31)	$ (1.33)	$ (3.01)
Weighted-average shares used in computing net loss per share attributable to Class A and Class B common stockholders - basic (in shares)	[1]	297,717,099	59,260,645	294,603,943	56,809,625
Weighted-average shares used in computing net loss per share attributable to Class A and Class B common stockholders - diluted (in shares)	[1]	297,717,099	59,260,645	294,603,943	56,809,625

[1] On March 1, 2021, all shares of the Company’s then-outstanding Class B common stock were automatically converted into the same number of shares of Class A common stock, pursuant to the terms of the Company’s amended and restated certificate of incorporation. No additional shares of Class B common stock will be issued following such conversion. See Note 11 for further details.