Research labs
Iterate on models without turning the editor into your research stack.
Critter Engine for robotics labs
Build the model. Understand the physics. Keep moving.
Give students and researchers a visual workspace for building, inspecting, testing, and sharing robot models—directly in the browser and without giving up standard robotics formats.
Core editor free · No install · Local-first by default
Bring robot models into Critter, inspect the physics, and export them back to your workflow.
Robotics courses
Spend class time on robotics instead of environment setup.
Project teams
Give the group a shared home without taking the free editor away.
Keep your research workflow at the center.
For research
Faster model iteration, without a proprietary dead end.
Bring in an existing robot, investigate what the model is actually doing, and export the result back to the tools your research already uses.
- See the whole physical model. Inspect bodies, joints, inertias, collisions, sites, tendons, actuators, and sensors in one visual workspace.
- Test ideas while they are still cheap. Run real-time physics in the browser before handing the model to training, controls, or hardware workflows.
- Work with the formats you already have. Import MJCF/XML and many URDF or Xacro projects, then export clean MJCF for current MuJoCo 3.x runtimes.
- Capture evidence, not just impressions. Inspect live sensor data and export recordings for analysis outside Critter.
For teaching
Make robot physics visible from day one.
Students can open the editor and start exploring without installing Docker, rebuilding a Python environment, or learning XML before they can see a joint move.
Start together
One browser-based environment
A consistent workspace across student machines, with local editing available without an account.
Learn by seeing
Visual structure and feedback
Connect the model hierarchy, joint axes, collision geometry, and inertial choices directly to simulated behavior.
Teach the standard
Real physics, inspectable models
Critter works with standard robot formats rather than hiding the model. Students can take exported MJCF into code when they are ready.
Choose your boundary
AI is optional
Use the visual editor on its own, or make the assistant part of a lab workflow when it fits the learning objective.
Less setup. More robotics.
Every student starts in the same browser-based editor. When it is time to write code, they can export the model as MJCF and continue in the course's existing programming workflow.
Free for building. Paid for coordinating.
Individuals get the editor. Labs get an operating home.
A generous free editor lets every student or researcher begin. Team plans are for the ownership, coordination, and support that appear when the work becomes shared.
Individual
Explore and build free
For a student, researcher, or engineer working independently.
- Visual robot editing
- Browser-based MuJoCo physics
- Local project files
- Standard import and export
Lab or course
Coordinate the work as a team
For faculty and lab leads who need the work to belong to the group.
- Lab-owned shared projects
- Member roles and permissions
- Cloud versions, comments, and sharing
- Centralized assistant access and usage
If everyone is working independently, the free editor may be all you need. The team plan becomes useful when the lab needs continuity, shared ownership, and coordination.
A shorter path to useful work
From source model to experiment in one continuous loop.
- 01
Bring the robot in
Import an existing model or begin with a familiar robot from the library.
- 02
Inspect and change it
Work directly with the physical structure instead of hunting through files.
- 03
Run the physics
Exercise joints, constraints, sensors, contacts, and behaviors in the browser.
- 04
Take it downstream
Export the model or recordings and continue in your research or course stack.
Questions from labs
Start with the workflow you already have.
Does every student need a paid account?
No. The core in-browser editor is intended to remain free. A paid team plan is for shared lab ownership, coordination, cloud workflows, and assistant access.
Does Critter replace our simulator or research code?
No. Critter uses MuJoCo for its browser physics and works with standard robot formats so models can continue into the tools, scripts, controllers, and training workflows your lab already uses.
Can projects stay local?
Yes. Local editing and portable .critter project files work without an account. Cloud projects and sharing are optional.
Is the AI assistant required?
No. Critter is a visual robot editor and simulation environment without the assistant. Labs can choose whether AI belongs in their research or teaching workflow.
A founding lab pilot
Bring one course, one project, or one robot.
Research or teaching · Small cohort · Direct support