Azure Monitor vs Azure Sentinel: What's the Difference?

Searches for “Azure Monitor vs Azure Sentinel” usually come from a reasonable confusion: both products ingest logs, both live in the Azure portal, both query with KQL, and both can fire alerts. Microsoft’s renaming of Azure Sentinel to Microsoft Sentinel didn’t help.

The short answer: they’re not competitors — Sentinel runs on top of Azure Monitor’s data layer. The real question is whether you need the security layer, and what that layer costs. Let’s break it down.

What Azure Monitor actually is

Azure Monitor is Microsoft’s observability platform — the umbrella for everything operational:

• Metrics: near-real-time numeric telemetry from Azure resources (CPU, memory, request rates)
• Logs: resource logs, activity logs, and application logs collected into Log Analytics workspaces
• Application Insights: APM — distributed traces, dependency maps, performance profiling
• Alerts & dashboards: threshold and KQL-based alert rules, workbooks, Grafana integration

Its job is answering operational questions: Is the service healthy? Why is p95 latency up? What did this pod log before it crashed?

The data backbone is the Log Analytics workspace. This matters because everything else in this article — including Sentinel — sits on that same backbone.

What Microsoft Sentinel actually is

Sentinel is a cloud-native SIEM and SOAR platform. You enable it on a Log Analytics workspace, and it adds a security layer over data that’s already there (plus security-specific connectors for Microsoft 365, Entra ID, firewalls, and third-party sources):

• Analytics rules: scheduled KQL detections and Microsoft-curated threat rules
• Incidents: correlation of alerts into cases with owners, severity, and investigation graphs
• SOAR playbooks: automated response via Logic Apps (disable a user, isolate a VM, open a ticket)
• UEBA & threat intelligence: behavioral baselines and IOC matching
• Content hub: prebuilt detections and workbooks per data source

Its job is answering security questions: Is someone brute-forcing our VPN? Did this service principal just do something it never does? Which machines talked to that C2 domain?

The relationship in one picture

                        ┌────────────────────────┐
   Azure resources ───► │ Log Analytics          │ ◄─── M365 / Entra ID /
   apps, agents,        │ workspace              │      firewalls (connectors)
   App Insights         │ (the shared data layer)│
                        └───────────┬────────────┘
                                    │
                ┌───────────────────┴───────────────────┐
                ▼                                       ▼
        Azure Monitor                           Microsoft Sentinel
        ops alerts, dashboards,                 detections, incidents,
        APM, autoscale signals                  hunting, SOAR playbooks

Same data, two lenses. Which is exactly why the pricing model stings.

Pricing: where the overlap gets expensive

Both products bill per GB on the same ingested data:

Component	Cost (pay-as-you-go)
Log Analytics ingestion	~$2.76/GB
Microsoft Sentinel surcharge	~$2.46/GB analyzed
Security-relevant data, combined	~$5.22/GB
Extra retention (beyond included)	~$0.10/GB/month

Commitment tiers discount both meters at volume (e.g. ~$1.96/GB for Log Analytics at 100 GB/day), but the structure stays the same: security data is billed twice — once to land in the workspace, once for Sentinel to analyze it.

A concrete example at 50 GB/day of security-relevant logs:

• Log Analytics: 1,500 GB × $1.96 (commitment) ≈ $2,940/month
• Sentinel: 1,500 GB × $2.46 ≈ $3,690/month
• Total: $6,930/month ($83,000/year) before retention

For the full breakdown including the self-hosted comparison, see LogTide vs Azure Monitor.

So which one do you need?

You need Azure Monitor (or some observability stack) if you run anything on Azure, full stop. Operational telemetry isn’t optional.

You need Sentinel if:

• You have a SOC team (or an MSSP) that will actually triage incidents and tune detections
• You’re deep in the Microsoft security ecosystem (Defender, Entra ID, M365) — the native connectors and curated detections are genuinely good there
• Compliance requires a formal SIEM with incident management and audit trails

You probably don’t need Sentinel if:

• Nobody would own the incident queue — an unwatched SIEM is an expensive log archive
• Your detection needs are log-based and rule-driven rather than UEBA/ML-driven
• The $2.46/GB surcharge forces you to exclude data sources from security analysis to control cost — which defeats the purpose

That last failure mode is common: teams route only a fraction of their logs into the Sentinel-enabled workspace to cap the bill, and attackers live in the logs that didn’t make the cut.

The third option: take log-based detection off the meter

If what you need is detection on your logs — failed logins, suspicious process activity, anomalous API usage, firewall events — rather than the full Microsoft security suite, a self-hosted platform changes the economics entirely.

LogTide includes SIEM capabilities in the box: Sigma detection rules (the portable, community-driven detection standard), MITRE ATT&CK mapping, real-time alerting, and incident management — with no per-GB surcharge, because you run it on your own infrastructure. The same 50 GB/day scenario above runs on roughly $400/month of VM and storage, versus ~$6,930 for the Log Analytics + Sentinel pair — and you can afford to analyze all your logs, not just the ones that fit the budget.

It’s not a full Sentinel replacement — there’s no UEBA, no Logic Apps SOAR, no M365-native connectors. But for log-based detection with data sovereignty (your security telemetry never leaves your infrastructure), it covers what most teams outside a dedicated SOC actually use.

Bottom line

	Azure Monitor	Microsoft Sentinel	LogTide (self-hosted)
Category	Observability	SIEM / SOAR	Log management + SIEM
Primary question	Is it healthy?	Is it under attack?	Both, log-based
Data layer	Log Analytics	Log Analytics (same)	Your TimescaleDB/ClickHouse
Detection rules	KQL alerts (ops)	Analytics rules, UEBA, TI	Sigma rules, MITRE ATT&CK
Pricing	~$2.76/GB	+$2.46/GB on top	Infrastructure only
Best for	Every Azure workload	Microsoft-centric SOCs	Cost-conscious, sovereignty-first teams

Azure Monitor and Sentinel aren’t an either/or — one is the data and ops layer, the other a security product on top of it. The decision that actually affects your budget is whether per-GB security pricing fits how much log data you want eyes on. If it doesn’t, self-hosted log management with built-in SIEM is the lever that changes the equation.

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Related reading:

• LogTide vs Azure Monitor — full feature and cost comparison
• Cloud logging pricing breakdown — CloudWatch, GCP and Azure compared
• Security monitoring use case — Sigma rules and ATT&CK mapping in practice