Revenue - Schedule of total revenue by geographic areas (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Oct. 31, 2025	Oct. 31, 2024	Oct. 31, 2025	Oct. 31, 2024
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue	$ 628,309	$ 529,375	$ 1,768,725	$ 1,458,045
MongoDB Atlas-related
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue	470,399	362,604	1,305,262	1,016,142
Other subscription
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue	138,668	149,601	407,615	396,764
Services
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue	19,242	17,170	55,848	45,139
Americas
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue	380,004	325,076	1,077,115	881,958
EMEA
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue	175,348	140,744	487,074	400,864
Asia Pacific
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue	$ 72,957	$ 63,555	$ 204,536	$ 175,223