AirJelly vs Kastor (2026)
A side-by-side comparison of AirJelly and Kastor on pricing, features, and fit, so you can decide which is right for you.
Quick answer
AirJelly and Kastor are both strong choices, but they fit different needs. Choose AirJelly if you mainly need automatically collecting action items from back-to-back zoom or google meet calls without taking manual notes — its edge is completely passive capture means zero friction or behavior change required from the user. Choose Kastor if you need building multi-step research assistants that delegate subtasks to specialized sub-agents — its edge is completely free and open-source with no licensing fees or usage limits. AirJelly starts at Free; Kastor starts at Free.
Features compared
- Always-on background screen monitoring that automatically detects tasks and follow-ups across all your apps
- Fully local AI processing that keeps your data on your Mac without sending it to external servers
- Cross-app task capture covering email, chat, documents, and video meetings in a single unified view
- Passive task surfacing that works without manual input or workflow interruption
- Multi-agent orchestration framework for coordinating multiple AI agents simultaneously
- Open-source codebase with full transparency and community-driven development
- Extensible architecture supporting custom LLM backends and tool integrations
- Agent communication and context-sharing protocols for collaborative task execution
Pros & cons
- Completely passive capture means zero friction or behavior change required from the user
- Local-only processing provides strong privacy guarantees compared to cloud-based AI tools
- Free to download and use, lowering the barrier to entry for solo professionals
- Currently macOS only, leaving Windows and Linux users without access
- As a newer tool, the accuracy of task detection may still be maturing and could miss context-dependent items
- Completely free and open-source with no licensing fees or usage limits
- Gives developers full control over agent logic, memory, and integrations
- Active open-source community enables rapid iteration and community-contributed extensions
- Requires developer expertise to set up and configure compared to managed platforms
- Documentation and support may be limited compared to commercial multi-agent frameworks
The verdict
Choose AirJelly if
you mainly need to automatically collecting action items from back-to-back zoom or google meet calls without taking manual notes. Its edge: completely passive capture means zero friction or behavior change required from the user.
Choose Kastor if
you mainly need to building multi-step research assistants that delegate subtasks to specialized sub-agents. Its edge: completely free and open-source with no licensing fees or usage limits.
Frequently asked questions
Is AirJelly better than Kastor?
Neither is universally better. AirJelly is stronger for automatically collecting action items from back-to-back zoom or google meet calls without taking manual notes, with an edge in completely passive capture means zero friction or behavior change required from the user. Kastor is stronger for building multi-step research assistants that delegate subtasks to specialized sub-agents, with an edge in completely free and open-source with no licensing fees or usage limits. Pick based on your main task.
Which is cheaper, AirJelly or Kastor?
AirJelly starts at Free and Kastor starts at Free. Free tier: AirJelly — Full macOS app available as a free download with core task capture features included.; Kastor — Fully free and open-source.
What is AirJelly best for?
AirJelly is best for automatically collecting action items from back-to-back zoom or google meet calls without taking manual notes, catching follow-up requests buried in slack threads or email chains before they are forgotten, consolidating to-dos scattered across multiple tools like notion, gmail, and messages into one place.
What is Kastor best for?
Kastor is best for building multi-step research assistants that delegate subtasks to specialized sub-agents, automating complex workflows where multiple ai agents must collaborate and hand off results, prototyping agentic pipelines for startups or research teams without incurring api or platform costs.
Do AirJelly and Kastor have free plans?
AirJelly: Full macOS app available as a free download with core task capture features included.. Kastor: Fully free and open-source. Check each tool's pricing page for current limits, as plans change.