The world's leading hybrid Mamba-Transformer model, combining state space efficiency with attention power to deliver 256K context at unbeatable speeds.
Technical Specifications
- Provider
- AI21
- Category
- flagship
- Release Date
- 2024-08
- Batch API Discount
- 50% off async batch
- Consumer Subscription
- Free / Self-Hosted
- Reasoning Effort Control
- Fixed
- Structured Outputs
- Yes
- Output Modalities
- text
- Official Documentation
- Visit Official Docs ↗
Data Privacy, Licensing & Deployment Governance
Official Provider Release Intelligence, API Quotas & Agentic Specs
- Official API Model ID (SDK String)
- jamba-1-5-large
- Supported SDK & API Protocol
- OpenAI-Compatible REST / vLLM / SGLang / HuggingFace TGI
- Lifecycle & Deprecation Status
- Legacy Stable (Upgrade path available in AI21 lineup)
- Production Rate Limits (RPM & TPM)
- Unlimited (Hardware-bound on self-hosted GPU) / 10,000 RPM Cloud · Unlimited local throughput / 10M+ TPM Managed Cloud
- Long-Context Pricing Tier (>128K / >200K)
- Flat rate ($2/1M in) across full 256K window
- Prompt Cache Write & TTL Policy
- Cached input at $0.5/1M tokens
- Computer Use & Browser GUI Agent
- API / CLI Tool-Use & DOM Agent ready (no raw pixel desktop click loop)
- MCP & Parallel Tool Calling
- Native MCP Client/Server ready · Parallel function calling · 100% Strict JSON Schema
- Web Search Grounding & Code Sandbox
- Supported via external Tavily/Exa Search & E2B/Docker Sandbox tools
- Fine-Tuning & Distillation Support
- Full Weights SFT, LoRA, QLoRA, DPO & GRPO RL (Unsloth / Axolotl / Llama-Factory)
- Multimodal Tokenization Billing
- Text BPE (~4 chars/token)
- Weights Precision & Quantization
- BF16 / FP16, FP8 Dynamic, INT4 AWQ / GPTQ, GGUF (Q4_K_M / Q8_0)
- Minimum GPU VRAM Requirement
- 247 GB VRAM (4-bit Quantized) · 856 GB VRAM (Native BF16)
- Supported Inference Engines
- vLLM, SGLang, Ollama, llama.cpp, TensorRT-LLM, HuggingFace TGI
- System Card & Safety Framework
- Open-Weights System Card + Customizable Guardrail Layer (Llama Guard / ShieldGemma)
- Enterprise Compliance (SOC2 / HIPAA / ZDR)
- 100% Air-Gapped On-Premises / Private VPC · Full HIPAA, GDPR & SOC2 Control
Jamba 1.5 Large Cost, Context, Hardware & API Integration
For single-user chat, a $20/mo subscription caps your bill below this API volume.
Break-even point: ~51 requests/day equals $20/month.
Same Monthly Workload Cost Across Popular Reference Models
Live Prompt Paste Tokenizer & Cost Counter
Paste real system instructions, JSON schemas, or code to measure BPE token counts across tokenizers.
Hybrid Prompt Routing Cascade Simulator
Route routine queries to a fast lightweight model ($0.15/1M) and escalate only complex reasoning turns to Jamba 1.5 Large:
Benchmark Scores & 6-Axis Capability Radar
- SWE-bench Verified
- 41.2%
- GPQA Diamond
- 51%
- MMLU-Pro
- 70.2%
- HumanEval
- 86.5%
- Humanity's Last Exam
- 6.9%
- Terminal-Bench
- 26.5%
- SciCode
- 27.2%
- LiveCodeBench
- 45%
- AIME
- 54%
- Long-Context Reasoning
- 75%
- Chatbot Arena Elo
- 1275pts
Strengths
- Revolutionary Mamba-2 SSM architecture handles 256K context with constant-memory scaling
- Open weights available on Hugging Face for enterprise hosting
- Native support for 9 languages and structured JSON output
- Immune to quadratic attention slowdown on very long prompts
Limitations & Trade-offs
- Substantial GPU footprint (398B total parameters in memory)
- Output length limited to 4K tokens
Editorial Assessment
The crowning achievement of State Space Model (SSM) research in foundation models.
Best for: Enterprise long-context legal analytics, financial filings, and private Mamba hosting
Compare Jamba 1.5 Large
Frequently Asked Questions about Jamba 1.5 Large
How much does the Jamba 1.5 Large API cost per 1M tokens?+
Jamba 1.5 Large by AI21 is priced at $2 per 1M input tokens and $8 per 1M output tokens. With prompt caching enabled, cached input tokens cost $0.5 per 1M tokens, and asynchronous Batch API requests receive a 50% discount.
Should I use a $20/month subscription or the Jamba 1.5 Large pay-as-you-go API?+
A flat $20/month consumer subscription is predictable for daily interactive chat and manual coding. However, if you are building software, running automated workflows, or sending low-to-moderate volume with prompt caching enabled, the pay-as-you-go API is typically far more cost-effective and offers higher rate limits without manual UI caps.
How many words and pages fit in Jamba 1.5 Large's context window?+
Jamba 1.5 Large features a 256K tokens context window, which equals approximately 192,000 English words or ~512 standard single-spaced pages in a single prompt. Its maximum output generation per turn is 4,096 tokens.
Can I run Jamba 1.5 Large locally on my own GPU (Open Weights)?+
Yes, Jamba 1.5 Large (398B (94B active)) releases open weights that can be self-hosted locally or on private cloud GPUs using vLLM, Ollama, SGLang, or llama.cpp.
Does AI21 train on data sent to the Jamba 1.5 Large API, and is commercial use allowed?+
100% Isolated when self-hosted on private GPUs or VPC. License tier: Open-Weights Research & Commercial License. Full commercial ownership of generated outputs. Supported deployment channels include: Self-Hosted GPU (vLLM / Ollama), Private VPC, or Managed Serverless API.
How does Jamba 1.5 Large perform on coding and reasoning benchmarks?+
Jamba 1.5 Large achieves a composite Intelligence Index of 42/100, scoring 41.2% on SWE-bench Verified, 51% on GPQA Diamond, 70.2% on MMLU-Pro, and 1275 pts on Chatbot Arena Elo.
What is Jamba 1.5 Large best used for?+
Jamba 1.5 Large is best suited for: Enterprise long-context legal analytics, financial filings, and private Mamba hosting. Assessment: The crowning achievement of State Space Model (SSM) research in foundation models.
AI21 Family Lineage, Routing Tiers & Upgrade Path
Step down to a lighter sibling for high-volume routing or step up to AI21's flagship reasoning tier:
AI Glossary & Architecture Concepts
View full glossary →Key machine learning concepts and benchmarks relevant to Jamba 1.5 Large:
The basic unit of text that a language model processes, typically representing about 3 to 4 English characters or roughly 0.75 words. For example, the sentence "Artificial intelligence is fast" breaks down into about 5 tokens.
A standardized evaluation suite used to objectively measure and rank an AI model's capabilities across specific tasks — such as SWE-bench Verified for software engineering, AIME for competitive math, or MMLU for general knowledge.
The maximum number of tokens a model can consider at once — both the input it reads and the output it writes. A 1,000,000-token context window can hold roughly 750,000 English words in a single request.
The ability of a language model to recognize when an external capability is needed and output structured JSON arguments to invoke external APIs, databases, or terminal commands. The runtime executes the tool and passes results back to the model.
An open standard created by Anthropic that allows AI applications and agents to connect seamlessly to local filesystems, development environments, and third-party APIs via standardized server interfaces.
A cost and latency optimization where inference providers store pre-computed attention states for repeated prompt prefixes. Reusing cached tokens typically slashes API input costs by 50% to 90% and cuts TTFT substantially.
Benchmark scores, token prices, and rate limits evolve rapidly as AI labs release model updates. Always verify current specifications and pricing on the official provider documentation.