Jamba 1.5 Large — benchmark results

AI21's 398B-total/94B-active hybrid SSM-Transformer MoE (August 2024) with a 256K effective context, released under the Jamba Open Model License. Provider: AI21 Labs. Released 2024-08-22. Access: API.

Unified ELO 1483 ± 18, rank #866 of 1776 rated models, from 27 benchmark results.

Strongest benchmark results

BenchmarkScoreMetricPercentile
RULER96Avg Accuracy (%)100
HELM Lite68.57Mean win rate (self-reported)75.3
HELM (Stanford)63.7Mean Win Rate (%)67.8
HELM NaturalQuestions (Closed)39.37F1 (%)62.2
HELM WMT 201420.29BLEU-4 (%)61.1
HELM NaturalQuestions (Open)71.79F1 (%)52.2
BenchTable39.8Total Score (%)37.5
ProLLM - Q&A Assistant91.3Score (%)33.3
Chatbot Arena (Text)1289Elo32.6
Vals AI LegalBench74.16Accuracy (%)24
HELM NarrativeQA66.36F1 (%)23.3
AA MATH-50060.6Accuracy (%)21.3

Interactive version: theaggregate.ai/model?slug=jamba-1-5-large · How the rankings work · Data refreshed daily, snapshot 2026-07-22.