Microsoft 365 Copilot vs Sierra Comparison
Compare Microsoft 365 Copilot vs Sierra features, pricing, and more.
Last updated: November 2026
Microsoft 365 Copilot
6.6/10
An AI assistant built into Word, Excel, PowerPoint, Outlook and Teams that drafts, summarizes and analyzes work content from an organization's Microsoft 365 data.
Sierra
7.4/10
Sierra is an enterprise conversational AI platform that builds and runs customer service agents across chat, voice, SMS, WhatsApp and email.
Feature-by-Feature Comparison
| Feature | | |
|---|---|---|
| Scores | ||
| Overall Rating | 6.6/10 | 7.4/10 |
| Integration | 9/10 | 8/10 |
| Analytics | 6/10 | 8/10 |
| Customization | 6/10 | 9/10 |
| Ease of Use | 7/10 | 7/10 |
| Support | 6/10 | 8/10 |
| Cost | 4/10 | 2/10 |
| Scalability | 9/10 | 9/10 |
| Security | 8/10 | 9/10 |
| Output Quality | 6/10 | 9/10 |
| Pricing | ||
| Free plan | No | No |
| Cheapest paid plan | $25/user/mo Microsoft 365 Copilot Business | Contact for pricing |
| Estimated cost for 10 users | $252/mo Microsoft 365 Copilot Business | Contact for pricing |
| Features | ||
| AI Agents | ||
| Data Analysis | Not listed | |
| Enterprise Controls | ||
| Knowledge Base Search | ||
| Text Generation | ||
| Transcription | Not listed | |
| Chatbots | Not listed | |
| Voice and Audio | Not listed | |
| Workflow Automation | Not listed | |
Which One Should You Choose?
Why choose Microsoft 365 Copilot
- Higher Cost score (4/10 vs 2/10)
- Higher Integration score (9/10 vs 8/10)
- Better fit for small business (7/10 vs 1/10)
- Better fit for mid-market (7/10 vs 5/10)
Why choose Sierra
- Higher Customization score (9/10 vs 6/10)
- Higher Output Quality score (9/10 vs 6/10)
Pros & Cons
Microsoft 365 Copilot
Pros
- Works directly inside Word, Excel, PowerPoint, Outlook and Teams, so users don't need to switch to a separate tool.
- Grounds answers in the organization's own email, SharePoint and OneDrive data, and respects the tenant's existing security and compliance settings.
- Teams meeting summaries with action items save time for meeting-heavy teams.
- Copilot Business brought the price for organizations with up to 300 users down to $21 from $30 while keeping the same functionality.
Cons
- It is an add-on, so the per-user cost comes on top of the base Microsoft 365 license.
- Reviewers report inconsistent output quality across the Office apps.
- Some users report daily usage or message limits.
- Overlapping product names (Copilot, Copilot Pro, Copilot Business) have led buyers to purchase the wrong tier.
Sierra
Pros
- Outcome-based billing means customers usually pay only for resolved conversations or other agreed results, not for each seat.
- Three build options cover both CX teams and engineers: the no-code Agent Studio, the code-first Agent SDK, and Ghostwriter for building agents from SOPs.
- One agent runs across chat, voice, SMS, WhatsApp, email and ChatGPT, keeping context between channels.
- Its list of compliance attestations is broad, covering SOC 2, ISO 27001, ISO 42001, HIPAA, PCI DSS and FedRAMP.
- It has a strong roster of enterprise customers, including SiriusXM, ADT, Rocket Mortgage and SoFi.
Cons
- There is no public pricing, and competitor estimates put annual contracts at about $150,000 or more.
- There is no self-serve or trial tier, so small teams cannot try it on their own.
- Implementation is largely vendor-led, which can make customers depend on Sierra's team for changes.
- There are few public reviews (7 on Gartner Peer Insights) to verify claims against.
- Some reviewers say voice quality still falls short of human level, and that complex telephony setups depend on how far the integration goes.
