Exhibit 32.1

CERTIFICATION

PURSUANT TO 18 U.S.C. SECTION 1350 (AS ADOPTED PURSUANT TO SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002)

Pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002, William W. Smith Jr., the Chief Executive Officer of Smith Micro Software, Inc. (the “Company”), and Timothy C. Huffmyer, the Chief Financial Officer of the Company, hereby certify, that, to their knowledge:

1. The quarterly report on Form 10-Q for the period ended September 30, 2025 of the Company (the “Report”) fully complies with the requirements of Section 13(a) or 15(d) of the Securities Exchange Act of 1934, as amended; and

2. The information contained in the Report fairly presents, in all material respects, the financial condition and results of operations of the Company.

November 5, 2025	By	/s/ William W. Smith, Jr.
	William W. Smith, Jr.
	Chairman of the Board, President and Chief Executive Officer
	(Principal Executive Officer)
November 5, 2025	By	/s/ Timothy C. Huffmyer
	Timothy C. Huffmyer
	Vice President, Chief Operating Officer, Chief Financial Officer and Treasurer
	(Principal Financial and Accounting Officer)