v3.24.1.u1
Document and Entity Information - shares
 3 Months Ended
Mar. 31, 2024
May 02, 2024
Document Information [Line Items]    
Document Type 10-Q  
Amendment Flag false  
Document Period End Date Mar. 31, 2024  
Document Fiscal Year Focus 2024  
Document Fiscal Period Focus Q1  
Entity Registrant Name AMPLITUDE, INC.  
Entity Central Index Key 0001866692  
Current Fiscal Year End Date --12-31  
Entity Filer Category Large Accelerated Filer  
Entity Small Business false  
Entity Emerging Growth Company false  
Entity Shell Company false  
Title of 12(b) Security Class A Common Stock, $0.00001 par value per share  
Trading Symbol AMPL  
Security Exchange Name NASDAQ  
Entity Current Reporting Status Yes  
Entity Interactive Data Current Yes  
Entity Incorporation, State or Country Code DE  
Entity File Number 001-40817  
Entity Tax Identification Number 45-3937349  
Entity Address, Address Line One 201 Third Street  
Entity Address, Address Line Two Suite 200  
Entity Address, City or Town San Francisco  
Entity Address, State or Province CA  
Entity Address, Postal Zip Code 94103  
City Area Code 415  
Local Phone Number 231-2353  
Document Quarterly Report true  
Document Transition Report false  
Class A Common Stock    
Document Information [Line Items]    
Entity Common Stock, Shares Outstanding   88,471,438
Class B Common Stock    
Document Information [Line Items]    
Entity Common Stock, Shares Outstanding   33,369,488