Sierra
Sierra builds branded voice and chat agents for support, charging per resolved conversation rather than per seat.
Full Sierra record →Head to head
Sierra vs ChatGPT Agent
Sierra (Sierra) and ChatGPT Agent (OpenAI) both sit in Agents & Automation. ChatGPT Agent shipped more tracked changes in the last 30 days (7 vs 1). Every value below comes from the latest crawl of the vendors' own pages.
| Attribute | Sierra Sierra | ChatGPT Agent OpenAI |
|---|---|---|
| Segment | Agents & Automation | Agents & Automation |
| Version | Agent OS 2.0 | gpt-6-astra |
| Entry cost | Pricing is not published (outcomes-based model: pay for results, not tokens). Contact sales. | from $20/mo |
| Pricing tiers | Outcome pricing free | ChatGPT Plus $20 |
| Model stack | Claude · GPT-5 class · Sierra Agent OS 2.0 | GPT-5.2 · GPT-5.4 · gpt-5.6 · gpt-6-astra |
| Context window | Model-dependent | 196K tokens |
| Public API | ||
| Routes models | ||
| Changes / 30d | 1 | 7 |
| Origin | Global | Global |
| Capabilities | Voice and chat agents, Agent OS, Brand persona control, Supervisor tooling, Outcome analytics, Horizon (Long-horizon agents), Ghostwriter (Agent-building agent), Agent Studio 2.0 | Virtual browser, Terminal access, Connectors, Takeover mode, Scheduled tasks, Agents SDK, Agent Builder, Computer use |
ChatGPT Agent
Controls a virtual browser and terminal to complete tasks end to end.
Full ChatGPT Agent record →