Character.AI vs Vellum
A side-by-side comparison of capabilities, autonomy, integrations, and pricing to help you choose.
Short answer: choose Character.AI if you want consumer platform for chatting with millions of user-created ai characters (Assistant, freemium); choose Vellum if you want platform to build, evaluate, and deploy llm apps and ai agents (Supervised agent, contact).
| Character.AI | Vellum | |
|---|---|---|
| What it is | Consumer platform for chatting with millions of user-created AI characters | Platform to build, evaluate, and deploy LLM apps and AI agents |
| Type | product-with-agents | platform |
| Autonomy | Assistant | Supervised agent |
| Pricing | freemium · Free; c.ai+ $9.99/mo (or $94.99/yr) | contact |
| Best for | consumers | developers, enterprise |
| Deployment | saas | saas, api |
| Modalities | text, voice, image, video | text, code, api |
| Models | proprietary | model-agnostic, gpt, claude, gemini |
| Protocols | none | mcp, function-calling, rest-api |
| Integrations | - | Composio, OpenAI, Anthropic, Google Gemini, AWS Bedrock, Cursor |
| Capabilities | 5 documented | 4 documented |
Character.AI
- +Enormous library of millions of user-created characters and a simple no-code character creator
- +Multimodal consumer experience: text, voice calls, group chat, image generation, and AvatarFX video
- +Runs on its own proprietary models, and the free tier historically had no hard message cap
- -Assistant-only: characters respond in chat and take no actions, with no tools, browsing, or automation
- -No public API and a closed proprietary model, so it cannot be embedded in external workflows
Vellum
- +Genuinely model-agnostic with a large, frequently updated catalog, avoiding lock-in
- +Covers the full LLM lifecycle (experiment, evaluate, deploy, monitor) in one place
- +Strong agent tooling with first-class MCP, Composio integrations, and auto-generated function-calling schemas
- -Brand and domain confusion: the apex vellum.ai domain appeared to host an unrelated product at this review
- -Platform pricing is not transparently published (sales-led, enterprise-leaning)
Which should you choose?
Character.AI is consumer platform for chatting with millions of user-created ai characters, best for consumers. Vellum is platform to build, evaluate, and deploy llm apps and ai agents, best for developers, enterprise. The right choice depends on the autonomy level you want, your existing integrations, and your budget, all compared above.