Model comparison · robotics
MolmoAct 2 vs SmolVLA 450M
Symmetrical, primary-source facts with unknown values left visible. No winner is assigned without comparable measurements.
FieldAt a glance
Ai2 · activeMolmoAct 2Verified Aug 28, 2026
Hugging Face LeRobot · activeSmolVLA 450MVerified Aug 28, 2026
Technical differences
Side-by-side facts
| Field | MolmoAct 2 | SmolVLA 450M |
|---|---|---|
| Developer | Ai2 | Hugging Face LeRobot |
| Family | MolmoAct 2 | SmolVLA |
| Model | MolmoAct 2 | SmolVLA 450M |
| Version | 2 | 450M |
| Lifecycle | active | active |
| Input modalities | Text, Image, Robot state | Text, Image, Robot state |
| Output modalities | Robot action | Robot action |
| Context window | Unknown | Unknown |
| Total parameters | 5000000000 | 450000000 |
| Active parameters | Unknown | Unknown |
| License | apache-2.0 | apache-2.0 |
| Open weights | Yes | Yes |
| API available | No | No |
| Self-hostable | Yes | Yes |
| Capabilities | action-reasoning, bimanual-manipulation, depth-reasoning, fine-tuning | asynchronous-inference, fine-tuning, low-cost-hardware, manipulation |
| Robotics model type | Action reasoning model | Vision-language-action model |
| Action representation | Flow-matching continuous action expert | Continuous action chunks from a flow-matching action expert |
| Control architecture | Molmo 2-ER backbone with KV-cache bridge and action expert | SmolVLM2 backbone with flow-matching action expert |
| Inference location | Flexible | On device |
| Native control rate (Hz) | Unknown | Unknown |
| Supported embodiments | SO-100, SO-101, Franka, WidowX, bimanual YAM | SO-100, SO-101, LeKiwi, LIBERO Franka |
| Training data | Open bimanual YAM, SO-100/SO-101, DROID, BC-Z, Fractal, Bridge, and prior MolmoAct data described by Ai2. | Compatibly licensed LeRobot community datasets totaling fewer than 30,000 episodes in the cited release. |
19 comparable fields · 12 material differences · Editorially curated pair passes the primary-source comparison gate
Primary benchmark evidence
Comparable performance
No protocol-matched benchmark yet.Results appear here only when both models share the same benchmark version, metric, evaluation protocol, and evidence class.
MolmoAct 2 capabilities
Input price—
Output price—
Serving providers0
Canonical IDallenai/MolmoAct2
SmolVLA 450M capabilities
Input price—
Output price—
Serving providers0
Canonical IDlerobot/smolvla_base
Internal comparison graph
Related comparisons
Primary evidence