The best online banking platforms in 2026

, , and anchor startup banking with distinct strengths: Mercury emphasizes streamlined accounts, virtual cards, and treasury workflows; Brex unifies corporate cards, spend controls, and accounting automations; Arc pairs rapid onboarding with high‑yield cash and capital access. Choices hinge on priorities—hands‑on treasury and APIs (Mercury), advanced spend governance and rewards (Brex), or yield maximization plus responsive support and financing (Arc).