Five9 vs Sierra
Five9 vs Sierra, compared side by side on 21 data points: what each one does, how big it is, what it has raised, the tech running each site, and what users report. We score both out of 100 on traction, team and visibility: Five9 is on 62/100 and Sierra on 62/100.
Where each one leads
Five9
- headcount: 3,051 against 277
- LinkedIn following: 121,557 against 29,888
Sierra
- agent readiness: 50/100 against 41/100
- funding raised: $1.6B against $71.6M
At a glance
| Measure | Five9 | Sierra |
|---|---|---|
| What it is | Cloud contact center software provider. | Sierra helps businesses build better, more human customer experiences with AI agents that can understand, reason, and take action across various channels. |
| Category | Artificial Intelligence, Customer Service, Cloud Computing, Cloud Contact Center Software | Agentic AI, Conversational AI, Customer Service, AI Agents |
| Sells toBusiness model | B2B | B2B |
| Offering | Software | Not published |
| Founded | 2001 | 2023 |
| Headquarters | San Ramon, USA | United States |
| Status | Active | Active |
Size, funding and growth
| Measure | Five9 | Sierra |
|---|---|---|
| Employees | 3,051 | 277 |
| Total funding | $71.6M | $1.6B |
| Latest round | Series D | Growth |
| Valuation | $1.1B | $10K |
| LinkedIn followers | 121,557 | 29,888 |
StartupHub scores
Our own 0-100 ratings. They measure company strength and site quality, not which product suits you.
| Measure | Five9 | Sierra |
|---|---|---|
| StartupHub scoreOur 0-100 rating | 62/100 | 62/100 |
| Traction | 59/100 | 60/100 |
| Team | 70/100 | 50/100 |
| Community | 15/100 | 8/100 |
| Search visibility | 45/100 | 78/100 |
| Quality | 68/100 | 65/100 |
| Agent readinessHow well an AI agent can read and act on the site | D (41/100) | D (50/100) |
| Domain ratingLink authority, 0-100 | 77/100 | 73/100 |
Technology
Detected on each public site, so it reflects the marketing stack as well as the product.
| Measure | Five9 | Sierra |
|---|---|---|
| Hosting | Self Managed | Vercel |
| CDN | Not detected | Cloudflare |
| CMS | Not detected | Ghost |
| Frameworks | Tailwind CSS, Bootstrap | Next.js, Tailwind CSS |
| Analytics | Google Tag Manager | Not detected |
| Support stack | Not detected | HubSpot |
Product and pricing
| Measure | Five9 | Sierra |
|---|---|---|
| Key features | Not published | AI Agent Deployment, Real-time Customer Support, Voice Communication Integration, Agent OS for Scalability, Actionable AI Integration, Robust Security & Compliance |
Five9 vs Sierra: common questions
Which is better, Five9 or Sierra?
Both score the same on our 0-100 rating, so the choice comes down to the 21 data points in the tables above rather than overall company strength.
How do Five9 and Sierra compare on the numbers?
Five9 leads on headcount (3,051 against 277), LinkedIn following (121,557 against 29,888). Sierra leads on agent readiness (50/100 against 41/100), funding raised ($1.6B against $71.6M).
Read the full Five9 review and pricing or the Sierra review and pricing. You can also browse other Five9 alternatives we track.