# Microsoft Defender XDR vs ReliaQuest GreyMatter: side-by-side comparison (2026)

[Microsoft Defender XDR](https://cybersectools.com/tools/microsoft-defender-xdr) is a commercial [extended detection and response](https://cybersectools.com/categories/xdr) solution by [Microsoft](https://cybersectools.com/companies/microsoft). [ReliaQuest GreyMatter](https://cybersectools.com/tools/reliaquest-greymatter) is a commercial [extended detection and response](https://cybersectools.com/categories/xdr) solution by [ReliaQuest](https://cybersectools.com/companies/reliaquest). Features, integrations, deployment and the company behind each one, side by side.

## Side-by-side comparison

| | Microsoft Defender XDR | ReliaQuest GreyMatter |
|---|---|---|
| Pricing model | Commercial | Commercial |
| Category | Extended Detection and Response | Extended Detection and Response |
| Verified | No | No |
| Deployment type | Cloud | Cloud |
| Company size fit | SMB, Mid-Market, Enterprise | SMB, Mid-Market, Enterprise |
| Company | Microsoft | ReliaQuest |
| Headquarters | – | – |

### Use cases and capabilities

| | Microsoft Defender XDR | ReliaQuest GreyMatter |
|---|---|---|
| MITRE ATT&CK | Yes | – |
| Security Orchestration | – | Yes |

### Core features

**Microsoft Defender XDR**

10 features listed. Sign in on the page to see them.

**ReliaQuest GreyMatter**

10 features listed. Sign in on the page to see them.

### Integrations

**Microsoft Defender XDR**

3 integrations listed. Sign in on the page to see them.

**ReliaQuest GreyMatter**

34 integrations listed. Sign in on the page to see them.

## Microsoft Defender XDR vs ReliaQuest GreyMatter FAQ

Common questions when comparing Microsoft Defender XDR vs ReliaQuest GreyMatter for extended detection and response.

### What is the difference between Microsoft Defender XDR and ReliaQuest GreyMatter?

**Microsoft Defender XDR**: XDR solution for unified detection and response across Microsoft 365. Built by Microsoft.

**ReliaQuest GreyMatter**: Agentic AI security operations platform for autonomous threat investigation. Built by ReliaQuest.

The table above shows where their features, integrations, deployment and company size fit differ.

### Who makes Microsoft Defender XDR and ReliaQuest GreyMatter?

**Microsoft Defender XDR** is made by Microsoft. **ReliaQuest GreyMatter** is made by ReliaQuest. The vendor behind a product decides its roadmap, support, and longevity, so check each company's profile before you commit.

### Is Microsoft Defender XDR a good alternative to ReliaQuest GreyMatter?

Often, yes. Microsoft Defender XDR and ReliaQuest GreyMatter are both Extended Detection and Response products. Use the table above to see where features, deployment and company size fit differ.

## Related comparisons

- [Microsoft Defender XDR vs ThreatDefence SecOps Platform](https://cybersectools.com/compare/microsoft-defender-xdr-vs-threatdefence-secops-platform)
- [Microsoft Defender XDR vs Cisco XDR](https://cybersectools.com/compare/cisco-xdr-vs-microsoft-defender-xdr)
- [Microsoft Defender XDR vs Seqrite XDR](https://cybersectools.com/compare/microsoft-defender-xdr-vs-seqrite-xdr)
- [ReliaQuest GreyMatter vs ThreatDefence SecOps Platform](https://cybersectools.com/compare/reliaquest-greymatter-vs-threatdefence-secops-platform)
- [ReliaQuest GreyMatter vs Cisco XDR](https://cybersectools.com/compare/cisco-xdr-vs-reliaquest-greymatter)
- [ReliaQuest GreyMatter vs Seqrite XDR](https://cybersectools.com/compare/reliaquest-greymatter-vs-seqrite-xdr)

## Alternatives to each

- [See all Microsoft Defender XDR alternatives](https://cybersectools.com/alternatives/microsoft-defender-xdr)
- [See all ReliaQuest GreyMatter alternatives](https://cybersectools.com/alternatives/reliaquest-greymatter)

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Source: https://cybersectools.com/compare/microsoft-defender-xdr-vs-reliaquest-greymatter

For AI agents: each product above has its own Markdown page (add .md to its URL, for example https://cybersectools.com/tools/microsoft-defender-xdr.md). Every CybersecTools shortlist is listed at https://cybersectools.com/shortlists.md.

More on Microsoft Defender XDR and ReliaQuest GreyMatter: funding, momentum, hiring and news, plus the full product and company record, are available through the Mandos MCP Server (paid plans), which connects to AI assistants: https://mandos.io/mcp?utm_source=cybersectools.com&utm_medium=compare-md