The more useful question is not which product is best.
It is what makes one of them a better fit for your environment, your existing licenses and the people who will operate it.
The short answer
Start with four questions:
- Are you already paying for Microsoft endpoint security?
- Who will investigate and respond to alerts?
- Why are you considering changing what you have now?
- What does your own testing show in your environment?
Those questions can narrow the decision faster than a long feature checklist.
If you already have Microsoft, start there
Before buying another endpoint product, find out exactly what Microsoft security you already license.
Microsoft Defender for Endpoint Plan 1 is available with Microsoft 365 E3. Microsoft 365 E5 includes Defender for Endpoint Plan 2. Plan 2 includes Microsoft's endpoint detection and response (EDR) capabilities. Plan 1 does not. Server licensing is separate.
Sources: Microsoft Defender service description; Microsoft Learn, Defender for Endpoint Plan 1. Official vendor documentation.
That does not make Defender free, and it does not make Defender the automatic choice. It does mean the economics of the decision may be different for an organization already paying for Microsoft security.
One buying decision in our evidence makes this particularly clear.
Venerable
More than 1,000 endpoints. Microsoft 365 E5. A CISO and small security team.
The organization was paying for overlapping endpoint security while still lacking 24/7 coverage. It moved to Microsoft Defender for Endpoint and added eSentire MDR.
The useful lesson is not that every Microsoft customer should choose Defender.
It is that an organization already paying for endpoint protection should identify the remaining gap before buying another endpoint product. The missing piece may be technology. It may also be people.
Source: eSentire customer story. Vendor-published.
There are also real reasons organizations choose something else
Existing Microsoft licensing does not settle the decision.
Organizations sometimes replace or supplement existing endpoint security because of operational problems, security concerns, support, migration needs or what they learn during an evaluation.
Our evidence contains decisions moving in different directions.
SentinelOne to CrowdStrike: The Third Floor
1,100 endpoints and 250 servers.
The company had SentinelOne through an MSSP. Its published case describes problems including false positives, manual investigation burden and dissatisfaction with the existing service arrangement. It moved to CrowdStrike Falcon with Falcon Complete MDR.
Source: CrowdStrike customer story. Vendor-published.
Previous EDR to SentinelOne: Sequoia Group
More than 2,500 endpoints.
Sequoia said its previous EDR fell short on communication, roadmap transparency and timely updates. It selected SentinelOne and reported migrating more than 2,500 endpoints in under five days without downtime or service tickets.
This is a SentinelOne-published customer story. It documents the reported buying decision and migration. It does not independently prove SentinelOne is better than another product.
Source: SentinelOne customer story. Vendor-published.
Another reason to test all three
A 2026 Britam EDR procurement for 1,350 devices explicitly identified CrowdStrike Falcon, SentinelOne Singularity and Microsoft Defender for Endpoint as solutions vendors should consider.
That does not tell us which product won or which product is best. It does show that a real buyer considered these three products relevant to the same endpoint-security decision.
Source: Britam EDR solution deployment RFP. Buyer RFP, independent of the three vendors.
CrowdStrike, SentinelOne or Defender?
Do not reduce the decision to three columns of marketing claims.
Instead, look at the situation that could make each product worth serious evaluation.
Microsoft Defender deserves a closer look when:
- You already have Microsoft 365 security licensing.
- You want to determine whether security you already pay for can meet the requirement.
- Integration with your wider Microsoft security environment matters.
- Your real gap may be 24/7 monitoring rather than another endpoint product.
Do not assume your Microsoft subscription includes everything you need. Check the exact Defender plan, server licensing and capabilities you currently have.
CrowdStrike deserves a closer look when:
- You are dissatisfied with your current endpoint product or service and CrowdStrike performs well in your own evaluation.
- You are considering endpoint protection together with managed detection and response.
- Your team wants to evaluate Falcon Complete as part of the operating model, not just Falcon as software.
- You are willing to evaluate the cost of a separate endpoint platform against what you already license elsewhere.
Our current evidence contains several organizations using CrowdStrike with managed services, including The Third Floor, GMG and Pella. These are vendor-published stories and should be treated as examples of buying decisions, not proof that CrowdStrike is universally better.
SentinelOne deserves a closer look when:
- You are replacing an EDR because of operational, support or product-fit problems.
- Migration and deployment behavior are important parts of your evaluation.
- You want to compare SentinelOne directly with CrowdStrike rather than assuming the better-known product is automatically the better fit.
- You want to test how the product behaves with your endpoints, applications and team.
Our current SentinelOne evidence is thinner than our CrowdStrike evidence.
What independent testing can tell you
Independent testing is useful, but it should not become a fake league table.
MITRE ATT&CK Evaluations are designed to show how security products detect and report attacker behavior under defined scenarios. MITRE explicitly does not rank the vendors.
Its Enterprise Round 6 included Microsoft and SentinelOne.
Source: MITRE news release. Independent evaluation.
AV-Comparatives' Business Security Test for March through June 2026 included Microsoft and CrowdStrike.
In that specific test, Microsoft recorded a 98.8% protection rate and zero false alarms. CrowdStrike recorded a 98.5% protection rate and eight false alarms.
That is one test, under one methodology, during one period. It does not show that one product beats the other.
Source: AV-Comparatives Business Security Test 2026 (March-June). Independent test.
AV-Comparatives also published a new Endpoint Prevention and Response test in September 2026. We do not use that report to compare CrowdStrike, SentinelOne and Microsoft, because its published named products do not provide a valid three-way comparison of these vendors.
The practical lesson is simple:
Independent tests can help you find questions to investigate. They should not make the purchase for you.
Put the products through your own test
A proof of concept should answer questions about your environment, not reproduce a vendor demo.
Test:
- What does deployment look like on our real endpoints and servers?
- What legitimate activity generates alerts?
- What happens when the product detects suspicious behavior?
- How much investigation does our team have to do?
- How easy is it to understand what happened?
- How does it behave with our important applications?
- What happens on Windows, macOS and Linux systems we actually use?
- How difficult is removal, migration or rollback if we change products later?
- What security products and Microsoft licenses would become redundant?
- Who responds after hours?
Score the products against those answers rather than the quality of the sales demonstration.
One operational question CrowdStrike buyers should include
On July 19, 2024, a CrowdStrike content update caused widespread crashes on affected Windows systems. CISA confirmed the outage resulted from the CrowdStrike update and was not malicious activity.
CrowdStrike's subsequent review described additional testing, validation, staged rollout and customer-control measures intended to reduce the chance and impact of a similar problem.
This incident does not tell you whether to buy or reject CrowdStrike.
It does give buyers a useful evaluation question:
How does each vendor test, stage, control and recover from an endpoint update that goes wrong?
Ask CrowdStrike that question.
Ask SentinelOne and Microsoft the same question.
Sources: CISA bulletin (government); CrowdStrike post-incident report (vendor-published).
Do not forget the people operating it
Product selection and operating model are connected.
A strong EDR product still creates alerts, investigations and decisions.
If nobody on your team is watching at 3 AM, the question may not be only CrowdStrike vs SentinelOne vs Defender.
It may also be EDR alone vs EDR with MDR. See EDR vs MDR.
A better way to make the shortlist
Already paying for Microsoft?
Verify exactly what Defender coverage you have and test it before assuming you need another endpoint license.
Replacing an EDR you're unhappy with?
Document exactly why you are replacing it. Make CrowdStrike and SentinelOne prove they solve those problems during the evaluation.
Small security team?
Evaluate the product and the operating model together. A product your team cannot realistically monitor and investigate is not a complete solution.
Still close after testing?
Compare the complete cost, including endpoint and server licensing, managed response, implementation, support and products that would become redundant.
The decision
There is no evidence-supported universal winner among CrowdStrike, SentinelOne and Microsoft Defender.
The strongest buying process is:
Know what you already own. Know why you are considering a change. Know who will operate the product. Then make the vendors prove the difference in your environment.
That gives you a defensible decision even when the products themselves are close.
About the evidence
This guide combines real buying decisions, buyer procurement documents, official licensing information and independent security testing.
Vendor customer stories are labeled because they are useful evidence of what a customer reportedly chose and why, but they are not independent proof of product superiority.
Independent tests are also kept within their limits. Results from different tests, dates and methodologies should not be combined into a homemade product ranking.
If a source does not tell us something, we do not fill in the blank.