Is IIS Actually a Good Web Hosting Solution?
I get asked about IIS fairly regularly, usually from people who are either evaluating it for a new project or trying to decide whether to migrate away from it. It's one of those topics where the answer is genuinely "it depends", but that's a lazy answer on its own so let me actually break down when it makes sense and when it doesn't.
What IIS is, quickly
IIS, Internet Information Services, is Microsoft's web server, built into Windows Server. It's been around since the mid-90s and has matured considerably over that time. It handles HTTP, HTTPS, FTP, and a handful of other protocols, and it's deeply integrated into the Windows ecosystem. If you've worked in a Windows-heavy environment you've almost certainly encountered it.
It's not a niche product either. A significant chunk of the web runs on IIS, particularly in enterprise environments that have standardised on Microsoft infrastructure. So the question isn't really whether it's a legitimate piece of software, it clearly is, but whether it's the right choice for a given situation.
Where IIS genuinely shines
The honest answer is that IIS is excellent in the right context, and that context is pretty specific: Windows-centric environments running .NET applications.
If your stack is built on ASP.NET or ASP.NET Core and you're already running Windows Server infrastructure, IIS is the natural fit. The integration is seamless in a way that's hard to replicate with other web servers on Windows. Application pools, worker process management, the integration with Active Directory for authentication, the tight coupling with the .NET runtime, all of that just works without a lot of configuration overhead. You're not fighting against the platform, you're working with it.
The management interface is also genuinely good. IIS Manager is a proper GUI that gives you a clear view of your sites, application pools, bindings, SSL certificates, and everything else. For teams that aren't heavily command-line focused or for environments where multiple people need to manage web infrastructure without being deep technical specialists, that matters.
Windows-native authentication is another area where IIS has a real advantage. If you're hosting internal applications that need to integrate with Active Directory and you want Kerberos or NTLM authentication, IIS handles this natively. Getting the same thing working cleanly on Nginx or Apache on Linux requires considerably more effort.
Where it falls short
Outside of that Microsoft-centric context the case for IIS gets weaker pretty quickly.
The Windows-only constraint is the obvious one. IIS doesn't run on Linux, which matters a lot in a world where Linux dominates server infrastructure for good reasons, cost, performance, flexibility, tooling. If you're running a mixed environment or you're trying to keep your hosting infrastructure consistent, IIS creates a platform silo.
Licensing cost is a real consideration too. Windows Server licenses aren't cheap, and when you're comparing against running Nginx or Apache on Linux, which costs nothing, that's a meaningful difference at scale. For a single server it might be negligible, but across a larger infrastructure it adds up.
Performance is another area where IIS trails. For high-throughput scenarios, particularly serving static content or acting as a reverse proxy, Nginx in particular is hard to beat. IIS has improved over the years but it's never been the performance leader in web serving benchmarks.
There's also the security attack surface to consider. IIS has historically been a target, partly because of its prevalence, partly because Windows Server environments tend to attract more targeted attacks than equivalent Linux setups. This doesn't mean IIS is insecure, it means you need to be on top of patching and configuration hardening consistently. In environments where that discipline exists it's fine. In environments where it doesn't, it's a risk.
The PHP and non- .NET question
One thing that comes up a lot is running PHP on IIS. It works, Microsoft has put effort into PHP support through FastCGI, but it's never felt like a first-class experience compared to running PHP on Linux with Nginx or Apache. You can make it work but you're going against the grain of how the PHP ecosystem is built and tested. Most PHP documentation, most hosting panels, most deployment tooling assumes Linux. You'll spend more time on platform-specific issues than you should.
Same goes for most other open source web technologies. They run on Windows, but Linux is where they're developed, tested, and optimised. Choosing IIS for a non-.NET stack means accepting that friction.
So is it good?
Yes, conditionally. IIS is a mature, capable web server that is genuinely the best choice for .NET applications running in Windows environments. If that describes your situation, use it without hesitation. The integration, the management tooling, and the Windows authentication support make it the right tool for that job.
If you're outside that context, running PHP, Python, Node, or anything else on a stack that isn't already committed to Windows, there are better options. Nginx and Apache on Linux are going to give you better performance, lower cost, and a smoother experience with the broader open source ecosystem.
The mistake I see people make is treating this as a religious debate rather than a practical one. IIS isn't universally good or bad, it's the right answer to a specific set of requirements. Know your requirements, make the call accordingly.