Evolv Technologies Holdings, Inc. Quarterly report pursuant to Section 13 or 15(d)

Warrants (Details) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended			3 Months Ended			9 Months Ended
	Dec. 31, 2020	Mar. 31, 2020	Feb. 28, 2019	Sep. 30, 2021	Mar. 31, 2021	Mar. 31, 2020	Sep. 30, 2021	Sep. 30, 2020
Class of Warrant or Right [Line Items]
Warrants to purchase shares of common stock	1,938,096			14,325,000			14,325,000
Issuance of equity classified warrants					$ 1	$ 45		$ 45
Changes in the fair value of warrants				$ (42)			$ 879
2019 SVB Common Stock Warrant
Class of Warrant or Right [Line Items]
Warrants to purchase shares of common stock			28,350
Exercise price			$ 0.24
2020 SVB Common Stock Warrant
Class of Warrant or Right [Line Items]
Warrants to purchase shares of common stock		280,095				280,095
Exercise price		$ 0.40				$ 0.40
2020 JPM Common Stock Warrant
Class of Warrant or Right [Line Items]
Warrants to purchase shares of common stock	378,000
Exercise price	$ 0.42
Public Warrant
Class of Warrant or Right [Line Items]
Warrants to purchase shares of common stock				14,325,000			14,325,000
Exercise price				$ 11.50			$ 11.50
Issuance of equity classified warrants							$ 23,600
Changes in the fair value of warrants							$ 3,200
Maximum \| 2019 SVB Common Stock Warrant
Class of Warrant or Right [Line Items]
Issuance of equity classified warrants			$ 100
Maximum \| 2020 SVB Common Stock Warrant
Class of Warrant or Right [Line Items]
Issuance of equity classified warrants		$ 100
Maximum \| 2020 JPM Common Stock Warrant
Class of Warrant or Right [Line Items]
Issuance of equity classified warrants	$ 100