Jamba 1.6 Large
by AI21 Labs · IsraelA Mamba-Transformer hybrid — state-space layers keep long-context memory flat instead of quadratic.
Specification
The numbers
- Maker
- AI21 Labs
- Released
- 2025-03
- Parameters
- 398B total / 94B active
- Architecture
- Hybrid SSM-Transformer
- Context window
- 256,000 tokens
- Max output
- 4,096 tokens
- Input
- Text
- Output
- Text
- Reasoning
- No
- Tool calling
- Yes
- Knowledge cutoff
- Not reported
- Licence
- Jamba Open Model
- Availability
- Not reported
- Weights
- Downloadable
Cost
Price per million tokens
- Input
- $2.00 / M tokens
- Output
- $8.00 / M tokens
- Blended 3:1
- $3.50
This model has open weights, so there is no first-party price. The figures above are a representative third-party hosting rate — you can also run it yourself for the cost of the hardware.
Published scores
Benchmarks
Figures published by AI21 Labs or taken from a public leaderboard. Row last checked 2026-08.
| Category | Score | Rank |
|---|---|---|
| ReasoningMulti-step logic on problems that cannot be looked up | Not reported | — |
| MathsCompetition mathematics, graded on the final answer | Not reported | — |
| CodingWriting and repairing real code | Not reported | — |
| KnowledgeMMLU-Pro | 60.0% | 41 of 77 reporting the same tests |
| MultimodalReading charts, diagrams and photographs | Not reported | — |
| Instruction followingIFEval | 88.0% | 6 of 15 reporting the same tests |
| Human preferenceWhich answer people pick, blind | Not reported | — |
A category averages every benchmark in it that Jamba 1.6 Large reports. The rank counts only models that report the same tests, so it never compares an average over three benchmarks against an average over one.
Every reported test
| MMLU-ProKnowledge | Rank 41 of 77 models reporting | |
|---|---|---|
| GPQA DiamondReasoning | Not reported | No figure published |
| AIME 2025Maths | Not reported | No figure published |
| MATH-500Maths | Not reported | No figure published |
| SWE-bench VerifiedCoding | Not reported | No figure published |
| SWE-bench ProCoding | Not reported | No figure published |
| Terminal-Bench 2.1Coding | Not reported | No figure published |
| Frontier-Bench v0.1Reasoning | Not reported | No figure published |
| Terminal-Bench 4.0Coding | Not reported | No figure published |
| LiveCodeBenchCoding | Not reported | No figure published |
| HumanEvalCoding | Not reported | No figure published |
| MMMUMultimodal | Not reported | No figure published |
| IFEvalInstruction following | Rank 6 of 15 models reporting | |
| LMArena EloHuman preference | Not reported | No figure published |
Where these numbers come from
Every score on this page is a published figure, taken from the model's own card, system card, technical report or release post, or from a public leaderboard. CorX Labs did not run these evaluations. Most are self-reported by the lab that built the model, which means they were produced under that lab's own choice of prompt, scaffold and number of attempts — so treat them as a starting point for a shortlist, not as a settled ranking.
A score someone other than the model's maker measured is marked Independent and names its measurer. Those are the stronger numbers on this page — an outside harness has no reason to flatter anyone — and there are not many of them.
Where a figure has not been published, the cell reads Not reported rather than an estimate. Nothing here is inferred, interpolated or guessed. Each model records the month its row was last checked. Full method and caveats.
Same maker
Other models from AI21 Labs
| Jamba 1.6 MiniAI21 Labs | AI21 Labs | 256K | $0.20 | $0.40 | 43% | — | — | — | Jamba Open Model |