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 | M Microsoft 365 Copilot | |
|---|---|---|
| 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 | ||
| Enterprise Controls | ||
| Knowledge Base Search | ||
| Text Generation | ||
| Chatbots | Not listed | |
| Data Analysis | Not listed | |
| Transcription | Not listed | |
| Voice and Audio | Not listed | |
| Workflow Automation | Not listed | |
Microsoft 365 Copilot vs Sierra cost by team size
| Team size | Microsoft 365 Copilot | Sierra |
|---|---|---|
| 1 user | $25/moMicrosoft 365 Copilot Business | Contact for pricing |
| 5 users | $126/moMicrosoft 365 Copilot Business | Contact for pricing |
| 10 users | $252/moMicrosoft 365 Copilot Business | Contact for pricing |
| 25 users | $630/moMicrosoft 365 Copilot Business | Contact for pricing |
| 50 users | $1,260/moMicrosoft 365 Copilot Business | Contact for pricing |
The plan that fits each team size, billed monthly, before add-ons and usage charges. Each cost opens that tool's pricing calculator for the team size.
Which One Should You Choose?
MWhy 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 freelancers (3/10 vs 1/10)
Why choose Sierra
- Higher Customization score (9/10 vs 6/10)
- Higher Output Quality score (9/10 vs 6/10)
Pros & Cons
MMicrosoft 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.
Not sold on either?
Frequently Asked Questions
Sierra scores higher on our AI Software criteria: 7.4/10 against 6.6/10 for Microsoft 365 Copilot. The largest gap is in Customization: 6/10 for Microsoft 365 Copilot and 9/10 for Sierra.
No, neither Microsoft 365 Copilot nor Sierra lists a free plan.
Microsoft 365 Copilot is the better fit for small business: we rate it 7/10 for them, against 1/10 for Sierra.
