X0508 4 2025-09-02 false 0001110611 ON24 INC. ONTF 0001335061 Vattuone Steven C/O ON24, INC. 50 BEALE STREET, 8TH FLOOR SAN FRANCISCO CA 94015 false true false false Chief Financial Officer true Common Stock 2025-09-02 4 S false 3222.00 5.6028 D 623099.00 D Common Stock 2025-09-03 4 S false 3549.00 5.4274 D 619550.00 D Common Stock 2025-09-04 4 S false 6394.00 5.5168 D 613156.00 D The transactions reported in this Form 4 was effected pursuant to a Rule 10B5-1 trading plan adopted by the reporting person on August 7, 2024. Represents the number of shares sold by the Reporting Person to cover tax withholding obligations in connection with the vesting of restricted stock units. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions ranging from $5.54 to $5.73, inclusive. The reporting person undertakes to provide to Issuer, any security holder of Issuer, or the staff of the Security and Exchange Commission, upon request, full information regarding the number of shares sold in each separate price within the ranges set forth in footnote (3) to this Form 4. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions ranging from $5.38 to $5.53, inclusive. The reporting person undertakes to provide to Issuer, any security holder of Issuer, or the staff of the Security and Exchange Commission, upon request, full information regarding the number of shares sold in each separate price within the ranges set forth in footnote (4) to this Form 4. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions ranging from $5.36 to $5.55, inclusive. The reporting person undertakes to provide to Issuer, any security holder of Issuer, or the staff of the Security and Exchange Commission, upon request, full information regarding the number of shares sold in each separate price within the ranges set forth in footnote (5) to this Form 4. /s/ Vattuone Steven by Charles Rogerson, as Attorney-in-Fact 2025-09-04