Jamba 1.5 Large/Mini is a Hybrid SSM-Transformer from AI21 Labs (Israel / United States).
One-line fit: best used for Long docs at better cost.
Key specifications
| Provider | AI21 Labs |
|---|---|
| Model | Jamba 1.5 Large/Mini |
| Type | Hybrid SSM-Transformer |
| Context window | 256K class |
| Pricing (indicative) | API |
| Company category | Enterprise LLM |
| Region | Israel / United States |
| Official site | https://www.ai21.com |
Benchmarks and public standing
Strong long-context efficiency claims
Treat scores as directional. SWE-bench, Terminal-Bench, LMSYS Arena, Artificial Analysis, and vendor cards use different harnesses and are not always comparable 1:1. Re-check the latest official model card before decisions.
What this model is good at
Long docs at better cost
This aligns with AI21 Labs’s broader strengths:
- Long documents
- Hybrid architecture efficiency
- Enterprise writing tools
Limitations and watch-outs
Smaller ecosystem than Big 3
- Rate limits, regional availability, and data retention policies vary by plan.
- Agent harness quality (Cursor, Claude Code, Codex, custom tools) can change outcomes more than raw model Elo.
- Open-weight availability (if any) is separate from hosted API quality and safety filters.
Ideal users
- Product engineers shipping features that match: Long docs at better cost
- Teams standardizing on the AI21 Labs ecosystem
- Agent builders who need a Hybrid SSM-Transformer
When to pick something else
- Cheaper volume: compare lower tiers from the same lab or open Chinese/EU alternatives.
- Maximum hard SWE thoughtfulness: compare Claude Fable-class and other coding flagships.
- Giant multimodal corpora / Workspace: compare Gemini-class models.
- Self-host / open weights: Llama, Qwen, DeepSeek, GLM, Mistral open lines.
Parent company
AI21 Labs – Jamba hybrid SSM-Transformer models for long-context enterprise document work.
Related models from AI21 Labs
- Jurassic lineage – Prior LLM
Data is curated for AIForumSphere model directory mid-2026 directional figures.
