August 18, 2025
With the release of .NET 9, Microsoft made a bold move: Swagger UI is no longer part of the default Web API template.
At first glance, this might feel like a step backward. Swagger has been a developer’s safety net for years spinning up a project and instantly exploring endpoints in the browser just worked. Now, all we get out-of-the-box is the OpenAPI spec (/openapi/v1.json).
But here’s my take: this isn’t a loss, it’s an opportunity.
The Bigger Picture
Microsoft is nudging us toward a more modular ecosystem. Instead of dictating one path (Swagger/Swashbuckle), they’re encouraging developers to pick the tool that fits best for their team, their workflow, and their product.
This aligns with a broader trend in software development: flexibility over convention. The “default” is being stripped back, and the community is empowered to innovate.
Exploring Alternatives
I recently read an excellent article by Round The Code that highlighted several strong alternatives worth considering:
- Postman: A classic, still unmatched for managing complex API testing and environments.
- NSwag: Lightweight, developer-friendly, and a near drop-in replacement for Swagger UI.
- Swashbuckle: Not gone, just optional. Add it back if your team still wants that familiar interface.
- Scalar: The exciting newcomer. Modern, customizable, and forward-looking potentially the tool that defines the next era of API exploration.
My Perspective
This shift resonates with how I approach development: don’t get too comfortable with defaults. Comfort zones breed stagnation.
Yes, Swagger made life easy, but maybe this is the right moment to ask: Is Swagger still the best fit? Or should we be exploring tools like Scalar that could shape our workflows for the next decade?
I see .NET 9’s change not as a disruption, but as an invitation:
- To revisit our assumptions.
- To experiment with alternatives.
- To level up how we design, test, and document APIs.
Final Thought
Credit where it’s due: Round The Code did a fantastic job unpacking this change. But the conversation doesn’t stop there.
👉 My question to you: how are you planning to adapt? Stick with Swashbuckle, try NSwag, lean into Postman, or bet on Scalar?