Ai2 · MolmoAct 2 · active

MolmoAct 2

Ai2's open action reasoning model for real-world robot control and post-training across single-arm and bimanual tasks.

allenai/MolmoAct2
Statusactive
InputText, Image, Robot state
OutputRobot action
Context
Total / active parameters5B /
Licenseapache-2.0
APINo
Open weights / self-hostYes / Yes

This page represents one immutable developer model ID. Serving endpoints, pricing, regions, quantizations, and service tiers attach separately and never create duplicate model records.

Provider availability

Serving endpoints and pricing

No directly sourced provider offerings yetPricing and availability stay unknown until collected from each serving provider.

Technical specification

Developer model IDallenai/MolmoAct2
Version2
ReleasedMay 5, 2026
ArchitectureMolmo 2-ER backbone with KV-cache bridge and action expert
Maximum outputUnknown
Knowledge cutoffNot reported

Capabilities

action-reasoningbimanual-manipulationdepth-reasoningfine-tuning
ReasoningYes
VisionYes
Tool callingNo

Version lineage

PredecessorUnknown
SuccessorsUnknown
Aliasesallenai/MolmoAct2

Explicit unknowns

  • Maximum output
  • Tokenizer
  • Knowledge cutoff
  • Provider pricing

Comparable peers

Related model comparisons

All comparisons →

Questions

MolmoAct 2 FAQs

What is MolmoAct 2?+

Ai2's open action reasoning model for real-world robot control and post-training across single-arm and bimanual tasks. It is developed by Ai2 and its current sourced lifecycle status is active.

What inputs and outputs does MolmoAct 2 support?+

MolmoAct 2's current record lists Text, Image, and Robot state as input and Robot action as output.

Is MolmoAct 2 available through an API?+

MolmoAct 2 is explicitly marked as not API-available in the current record.

How large is MolmoAct 2?+

The current record lists 5B total parameters and an unknown active parameter count. Its architecture is Molmo 2-ER backbone with KV-cache bridge and action expert.

What capabilities and tasks does MolmoAct 2 support?+

MolmoAct 2's recorded capabilities are action-reasoning, bimanual-manipulation, depth-reasoning, and fine-tuning. Its supported tasks are robot-control, dexterous-manipulation, and bimanual-manipulation.

Can MolmoAct 2 be self-hosted?+

MolmoAct 2 is an open-weight model. Self-hosting is supported, and the recorded license is apache-2.0.

Does MolmoAct 2 have related versions or aliases?+

No predecessor is recorded. No successor is recorded. Recorded aliases are allenai/MolmoAct2.

Which models can MolmoAct 2 be compared with?+

The current compatible peer set includes OpenVLA 7B, GR00T N1.7 3B, SmolVLA 450M, Helix 02, and pi 0.7. Compatibility requires shared sourced modalities and tasks; it does not imply that one model is better. Browse model comparisons

How current is the Model Markets record for MolmoAct 2?+

MolmoAct 2 was last verified Aug 28, 2026 from Ai2's primary source, “MolmoAct2 developer model repository.” The evidence is classified as official fact.

Primary evidence

Sources and observation date