Atomic Chat vs Onyx
Atomic Chat
atomic.chatOnyx
onyx.appSide by side
| Figure | Atomic Chat | Onyx |
|---|---|---|
| Price from | Free | $20/mo |
| Free plan | Yes | Yes |
| Free trial | — | Yes |
| Open source | — | Yes |
| Web | — | Yes |
| Windows | Yes | Yes |
| macOS | Yes | Yes |
| Linux | Yes | Yes |
| iOS | Yes | — |
| Android | Yes | — |
| API | Yes | Yes |
| Self-hosted | — | Yes |
| Plans published | 2 | 3 |
| Spec score · AI chatbots and assistants | 7.9 (#43) | 9.0 (#12) |
| File uploads | Yes | Yes |
| Free plan | Yes | Yes |
| Integrations | Its MCP connectors can connect to tools including Notion, Google Drive, Slack, GitHub, Figma and Supabase; it supports STDIO, HTTP and SSE transports. | The product advertises more than 50 synced connectors and names Slack, Google Drive, Confluence, Salesforce, GitHub and Jira among supported sources. |
| Support | The site lists support by email at [email protected]. | The Business plan includes Community Support; Enterprise lists Dedicated Support and an Enterprise SLA. |
| Web search | Yes | Yes |
| What it does | Atomic Chat runs language models locally on your device so you can chat with them offline after downloading a model. | Onyx connects organizational knowledge sources to chat, search, agents and AI workflows, acting as a context layer for people and agents. |
Plans
In their own words
Atomic Chat
Atomic Chat has no write-up on Specifiction yet; its figures are above.
Onyx
Onyx connects enterprise knowledge so people and AI agents can use relevant context in answers. It searches indexed sources in parallel and presents documents while enforcing each source's permissions. More than 50 connectors sync connected tools in the background and support hybrid semantic and keyword search. The Business plan lists chat and search, major LLM access, custom agents, MCP/OpenAPI actions, web search, deep research, code interpreter, and image generation. Business costs $20 a month, billed annually at $20 per user per month, for teams of any size, with 40+ app connectors and Community Support. Onyx provides APIs for messages, agents, LLM management, actions, and user authentication. Slack integrations can provide responses and agents; Microsoft Teams and Zendesk are described as coming soon. Deployments can run in a customer's cloud or on bare metal, including on-premise and fully air-gapped environments. The site says documents and embeddings can remain in customer infrastructure, data is not used for training, and permissions are checked at query time. Native Windows, macOS, and Linux apps connect to an existing deployment.