ADP Run vs Paychex Flex
Side-by-side from the Top 11 ranking of The 11 Best Payroll Software for SMBs. Last verified May 31, 2026.
The short answer
ADP Run ranks higher on Top 11 (#5 vs #6) for Small business owners running payroll without in-house HR. The SMB solution from an industry giant, offering unmatched reliability, compliance, and scalability.
At a glance
| ADP Run | Paychex Flex | |
|---|---|---|
| Top 11 rank | #5 / The 11 Best Payroll Software for SMBs | #6 / The 11 Best Payroll Software for SMBs |
| Score (out of 9.4) | 8.4 | 8.2 |
| Best for | Reliability and scalability | All-in-one HR services |
| Pricing | $$$ (Varies by quote) | $$$ (Varies by quote) |
| HQ | Roseland, USA | Rochester, USA |
| Founded | 1949 | 1971 |
ADP Run
The SMB solution from an industry giant, offering unmatched reliability, compliance, and scalability.
www.adp.com/what-we-offer/by-business-size/small-business.aspxPaychex Flex
A comprehensive HR platform from an industry veteran, ideal for businesses needing more than just payroll.
www.paychex.com/paychex-flexMethodology and scoring weights live at /methodology. No vendor pays for placement — see about.