We ran a React SPA admin panel for almost three years. It worked. Customers logged in, edited content, published articles. Bundle size kept creeping up. Build times kept creeping up. A new dev needed two weeks to be productive. We started skipping minor features because "the diff is too risky."
In Q3 2025 we migrated that panel to HTMX over six months, route by route. This post is the honest version of how it went — what worked, what we didn't see coming, and the numbers from running both stacks side by side across more than 200 production deployments.
The React tax in 2026
Let me get one thing out of the way: React isn't broken. It's a fine tool for the workloads it was designed for. Our admin panel was not one of those workloads. Most of our screens are forms, lists, and modal dialogs. The fanciest interaction is drag-to-reorder. The actual user count per tenant is small — usually 1 to 5 editors per site.
For that, here's what React was costing us:
