Summary of Significant Accounting Policies - Narrative (Details)	3 Months Ended		9 Months Ended
	Sep. 30, 2022 USD ($)	Sep. 30, 2021 USD ($)	Sep. 30, 2022 USD ($) reporting_unit segment	Sep. 30, 2021 USD ($)	Dec. 31, 2021 USD ($)
Cash and Cash Equivalents [Line Items]
Number of operating segments | segment			1
Allowance for doubtful accounts	$ 600,000		$ 600,000		$ 500,000
Amortization period	6 years		6 years
Impairments of capitalized internal use software	$ 0	$ 0	$ 0	$ 0
Number of reporting units | reporting_unit			1
Goodwill impairment	0	0	$ 0	0
Intangible asset impairment	0	0	0	0
Long-lived asset impairment	0	0	$ 0	0
Percentage of annual contributions per employee			100.00%
Percentage of vested annual eligible compensation			100.00%
Percentage of vested employer matching			100.00%
Vesting period			1 year
Contributions	1,100,000	500,000	$ 2,900,000	1,600,000
Advertising expenses	$ 6,800,000	$ 3,300,000	$ 18,300,000	$ 10,500,000
Common stock, conversion ratio	1		1
Money Market Funds
Cash and Cash Equivalents [Line Items]
Money market mutual funds	$ 116,600,000		$ 116,600,000		$ 180,200,000
Restricted stock units
Cash and Cash Equivalents [Line Items]
Vesting period			3 years
Performance-Based Restricted Stock Units
Cash and Cash Equivalents [Line Items]
Performance target (as a percent)			100.00%
Requisite service period (in years)			3 years
Shares issuable pursuant to the 2021 Employee Stock Purchase Plan
Cash and Cash Equivalents [Line Items]
Expense recognition period			6 months
Purchase shares discount (as a percent)			15.00%
Minimum
Cash and Cash Equivalents [Line Items]
Capitalized computer software, useful life			3 years
Capitalized computer content, useful life			3 years
Subscription contracts, term			1 year
Maximum
Cash and Cash Equivalents [Line Items]
Capitalized computer software, useful life			6 years
Capitalized computer content, useful life			7 years
Subscription contracts, term			3 years