Cover Page - shares	3 Months Ended
	Mar. 31, 2020	Apr. 30, 2020
Document Information [Line Items]
Document Type	10-Q
Document Fiscal Period Focus	Q1
Document Quarterly Report	true
Document Period End Date	Mar. 31, 2020
Document Transition Report	false
Amendment Flag	false
Document Fiscal Year Focus	2020
Current Fiscal Year End Date	--12-31
Entity File Number	001-38872
Entity Registrant Name	Pinterest, Inc.
Entity Central Index Key	0001506293
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	26-3607129
Entity Address, Address Line One	505 Brannan Street
Entity Address, City or Town	San Francisco
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	94107
City Area Code	415
Local Phone Number	762-7100
Title of 12(b) Security	Class A Common Stock, $0.00001 par value
Trading Symbol	PINS
Security Exchange Name	NYSE
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Class A Common Stock
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		403,489,955
Class B Common Stock
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		182,966,393