Nearly every Azure security design I review opens with the same discussion. Is Azure Firewall Standard enough, or do we actually need Azure Firewall Premium? Most production tenants stay on Standard, because Basic is missing too many essential features for any serious workload. Once intrusion prevention, TLS inspection or fine-grained web filtering show up in the requirements, though, Premium stops being a nice-to-have and becomes a real option.

Azure Firewall Premium can alert on IDPS signatures or block the traffic outright

The signature-based Intrusion Detection and Prevention System (IDPS) is still the main thing that separates Azure Firewall Premium from the lower tiers. Standard has no IDPS at all. Premium lets you choose between "alert only" and "alert and deny", and in the second mode attacks get blocked on the wire instead of just landing in a log. I mostly see this in regulated industries and in organizations that go through a lot of audits, where "deny" is often a box that has to be ticked. Signatures update automatically, and the coverage is wide enough to be useful without much tuning (Microsoft's feature overview).

This Mermaid diagram shows how the choice between Standard and Premium affects your IDPS options:

flowchart TD
    Start["Firewall requirement"] --> Standard["Azure Firewall Standard"]
    Start --> Premium["Azure Firewall Premium"]
    Standard -->|"No IDPS"| Monitoring["Logging only"]
    Premium -->|"Alert only"| Alarm["Attack detected"]
    Premium -->|"Alert and deny"| Block["Attack blocked"]

Figure: IDPS mode differences between Standard and Premium.

In hub-spoke and Virtual WAN topologies I'm seeing more and more pressure to turn on "deny". Compliance is one reason, but cyber insurance requirements are another, and they are very real. You can't get that kind of active blocking without Premium, and for internet-facing APIs it has turned into a hard requirement.

TLS inspection makes certain compliance requirements achievable

TLS inspection is a feature few people are keen to touch, yet many now need it. Azure Firewall Premium can transparently inspect inbound and outbound HTTPS using an intermediate CA certificate stored in Azure Key Vault (setup guide). You need a suitable certificate in Key Vault, and the firewall's managed identity needs access to it. The setup takes some care. Once it runs, it stays stable, and in several environments I currently manage it was the one feature that settled the Premium decision. In regulated sectors, or anywhere sensitive data passes through your firewall, inspection isn't optional anymore.

Practical tip: Before enabling TLS inspection, make sure your root CA is trusted by every client. If you miss this, expect headaches with app failures and support tickets.

URL filtering and web categories give you control directly at the firewall

Premium can also filter by web category and by specific URL. Standard only lets you work with IPs and FQDNs, while Premium lets you block or allow categories such as social media, streaming or file sharing. That matters a lot once works councils or HR get involved and the policy has to be enforced at the firewall. The structured Log Analytics tables (documentation), in particular AZFWNetworkRule, AZFWApplicationRule and AZFWIdpsSignature, speed up reporting and troubleshooting considerably.

Here's a KQL query I use to find denied web categories (Log Analytics workspace → Logs, role: Log Analytics Reader, diagnostic setting enabled):

AZFWApplicationRule
| where Action == "Deny" and isnotempty(WebCategory)
| summarize count() by WebCategory

Parent and child policies keep many firewalls consistent at scale

Azure Firewall Manager lets you manage multiple firewalls centrally through parent and child policies, which is a big help in larger hub-spoke or Virtual WAN setups. With Premium the hierarchy gets especially useful. You define the IDPS settings once in a parent policy, they flow down to every firewall, and the whole estate stays consistent. That has saved me hours during audits, rule changes and incident response.

Premium pays off only where you place it deliberately

None of this is cheap. Azure Firewall Premium can cost several times as much as Standard, and that's before Log Analytics charges. For that reason I rarely recommend putting Premium everywhere. What I usually see is Premium in the hub, inspecting north-south (internet) traffic, and Standard in spoke networks that only handle east-west flows. Virtual WAN deployments tend to follow the same pattern, with Premium at the edge and Standard everywhere else.

Your network architecture plays into this as well. If you use Private Endpoints and want tight control, you have to get the firewall integration and DNS right. I've covered the usual pitfalls in Private endpoints DNS in Azure: Common mistakes in practice. And now that "Default outbound access" in Azure has ended, every design should take another look at internet breakout: Default outbound access in Azure: End of an era, now what?.

I treat Premium as a targeted upgrade rather than the default

Azure Firewall Premium isn't for everyone. If you need IDPS, TLS inspection or granular web filtering, it's worth the money, provided you deploy it where it counts. Standard still handles basic east-west segmentation just fine. When compliance, SOC requirements or strict internet controls are part of the brief, Premium is often the only realistic option. Over time the structured logs and the policy hierarchy pay for themselves in auditability and troubleshooting. If you do go Premium, actually use the features. Otherwise it's just an expensive checkbox on your network diagram.