X0306 4 2021-09-28 0 0001866692 Amplitude, Inc. AMPL 0001744910 Wong Catherine C/O AMPLITUDE,INC. 201 THIRD ST., SUITE 200 SAN FRANCISCO CA 94103 1 0 0 0 Class A Common Stock 2021-09-28 4 A 0 125000 0.00 A 125000 D Class A Common Stock 2021-09-30 4 S 0 3515 53.9679 D 121485 D Constitute restricted stock units ("RSUs") for which the Reporting Person is entitled to receive one (1) share of Class A Common Stock for each RSU upon vesting. 1/16th of the RSUs vest on each quarterly anniversary of May 15, 2021, beginning August 15, 2021, subject to the Reporting Person's continued service to the Issuer. Includes 117,188 RSUs. Shares sold to satisfy tax withholding obligations in connection with the vesting of RSUs. This transaction was executed in multiple trades in prices ranging from $53.92 to $54.03, inclusive. The price reported in Column 4 above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide to the Securities and Exchange Commission staff, the Issuer, or a security holder of the Issuer, upon request, full information regarding the number of shares sold at each respective price within the range set forth in this footnote. /s/ Hoang Vuong, as Attorney-in-Fact for Catherine Wong 2021-09-30