AI21 Labs
Updated May 2026Jamba
Hybrid Mamba-Transformer models built for long context
Jamba is AI21's hybrid architecture family combining transformer attention with Mamba-style state space layers. The point is long context and throughput: process large documents without paying the full attention cost everywhere. Jamba is a useful teaching example because it shows that model architecture is not only about more layers; it is about matching the computation pattern to the workload.
Variants
4
Best at
long context with efficient architecture
Max context
256K
tokens
Pricing
Open weights
$0
per self-hosted model weights
AI21 Studio / Bedrock
varies
per hosted usage
Variants
Sort the table by context window or cost to find the right variant. Click any version below for a battle card with ranks, pricing notes, and official links.
| Modalities | ||||
|---|---|---|---|---|
Jamba 1.5 Large ai21labs/AI21-Jamba-Large-1.5 | 256K | varies / varies | 2024 | textcode |
Jamba 1.5 Mini ai21labs/AI21-Jamba-1.5-Mini | 256K | varies / varies | 2024 | textcode |
Jamba-Instruct jamba-instruct | 256K | varies / varies | 2024 | text |
Jamba 1.5a jamba-1.5a | 256K | varies / varies | 2025 | text |
Battle card
Context rank
#1
within Jamba
Capability rank
#1
modalities + reasoning
Weights
Open
self-hostable if licensed
Best fights to pick
- long document QA
- enterprise summarization
- large extraction jobs
Rankings are Tendril directory ranks, computed from the model data shown here. Public benchmark leaderboards change often, so official docs and current benchmark pages should be checked before buying or deploying.
Learn
Lessons about this model
Structured lessons that cover Jamba directly or put it in context alongside its rivals.
Jamba: Family Map
Jamba: Flagship Picker
Jamba: Cost And Context
Jamba: Reasoning Mode
Jamba: Multimodal Workflows
Jamba: Coding And Software Tasks
Jamba: Agents And Tool Use
Jamba: Local Or Private Deployment
Jamba: Benchmarks And Reality Checks
Jamba: Safety And Limits
Jamba: Prompt Recipes
Jamba: Industry Use Cases
Jamba: Compare Against Rivals
Jamba: Build A Mini Workflow
Jamba: Capstone Selection Memo
Check yourself
Quizzes
Short, mixed-difficulty quiz sets on Jamba and its model family.
Jamba Model Family Quiz
5 questions
A short quiz on where Jamba fits, which variants matter, and how to choose it responsibly.
Start quiz →Hands-on
Try these prompts
Ready-made prompts that show Jamba at its best. Use them in your own AI workspace, then compare the output with what you learned in Tendril.
Jamba same-task bakeoff
BuildersCompare Jamba against a cheaper and stronger rival on one real task.
Use Jamba for this task, then compare with one cheaper model and one stronger model: summarize a 10-page policy document into risks, decisions, owners, and open questions.
Jamba failure-mode log
CreatorsTrack where Jamba fails instead of only saving the best output.
Run this task three times. For every answer, mark failures as factual error, formatting error, weak reasoning, refusal, or missing citation.
Print & keep
Printable reference
One-page summaries and flowcharts — great for desks, classrooms, or study sessions.
Go deeper
Official resources
Straight from the lab — docs, API references, and the chat surfaces you can try today.
Strengths
- long context with efficient architecture
- open-weight enterprise models
- good teaching case for Mamba/SSM hybrids
Limits
- not a mainstream consumer chatbot
- requires serious hardware at larger sizes
- less broad ecosystem than Llama/Qwen