Language

Jamba 1.5 Large

By AI21 Labs, in the Jamba family.

Released
Aug 2024
Status
Retired
Retired
6 May 2025
Context
256K
Max output
—
Input per 1M tokens
—
Output per 1M tokens
—
Open weights
Yes
License
jamba-open-model-license
Parameters
398.56B, 94B active
Knowledge cutoff
—
Reasoning
No
Modalities
text → text

Category scores

Out of 100, from independent and third-party results only, by method category-2026-09-29.1.

Category scores
CategoryScoreRankCoverage
Human preference34.6Not ranked1 of 5

Benchmark results

Every result we hold for this model, with who ran it and where it was published.

Knowledge & reasoning

Knowledge & reasoning results
BenchmarkMetricValueProvenanceSettingEvaluatedSource
MMLU-ProAccuracy49.5%Self-reported——EvalEval via Hugging Face Community Evals

Human preference

Human preference results
BenchmarkMetricValueProvenanceSettingEvaluatedSource
Text Arena (arena.ai)Arena score (Elo scale)1289Independent—25 Sep 2026Arena
Text Arena (arena.ai)Votes8662Independent—25 Sep 2026Arena

Other Jamba versions

Sources