Jamba 1.5 MinivsGPT-o3
AI21 Labs vs OpenAI — Side-by-side model comparison
Head-to-Head Comparison
| Metric | Jamba 1.5 Mini | GPT-o3 |
|---|---|---|
| Provider | ||
| Arena Rank | — | #2 |
| Context Window | 256K | 200K |
| Input Pricing | $0.20/1M tokens | $2.00/1M tokens |
| Output Pricing | $0.40/1M tokens | $8.00/1M tokens |
| Parameters | 52B (12B active) | Undisclosed |
| Open Source | Yes | No |
| Best For | Cost-effective long-context, summarization | Advanced reasoning, agentic tasks, research |
| Release Date | Aug 22, 2024 | Apr 16, 2025 |
Jamba 1.5 Mini
Jamba 1.5 Mini, developed by AI21 Labs, is a compact hybrid SSM-Transformer model with 52 billion total parameters (12 billion active) and a 256K token context window. The model applies AI21 Labs' hybrid Mamba-Transformer architecture in a smaller, more efficient package designed for cost-effective long-context processing. It handles summarization, document analysis, and RAG tasks with the efficiency advantages of state-space models on long sequences. Priced at $0.20 per million input tokens and $0.40 per million output tokens, it offers affordable access to long-context processing. As an open-source model, Jamba 1.5 Mini can be deployed on more modest hardware compared to its larger sibling. The model targets production applications where processing long documents efficiently at low cost matters more than achieving maximum benchmark scores.
View AI21 Labs profile →GPT-o3
GPT-o3 is OpenAI's most advanced reasoning model, succeeding o1 as the frontier of deliberative AI. It uses an enhanced chain-of-thought approach where the model spends more compute time 'thinking' before responding, dramatically improving performance on complex STEM, mathematical, and logical reasoning tasks. With a 200K token context window and the ability to use tools during reasoning, o3 represents a significant leap in AI problem-solving capabilities. It achieved state-of-the-art results on the ARC-AGI benchmark, demonstrating near-human performance on novel reasoning challenges. The model is particularly strong at multi-step mathematical proofs, complex code debugging, and scientific analysis where careful step-by-step reasoning is essential. Originally priced at a premium, an 80% price reduction in June 2025 made o3 accessible to a much broader range of developers and applications.
View OpenAI profile →Key Differences: Jamba 1.5 Mini vs GPT-o3
Jamba 1.5 Mini is 16.7x cheaper on average, making it the better choice for high-volume applications.
Jamba 1.5 Mini supports a larger context window (256K), allowing it to process longer documents in a single request.
Jamba 1.5 Mini is open-source (free to self-host and fine-tune) while GPT-o3 is proprietary (API-only access).
When to use Jamba 1.5 Mini
- +Budget is a concern and you need cost efficiency
- +You need to process long documents (256K context)
- +You need to self-host or fine-tune the model
- +Your use case involves cost-effective long-context, summarization
When to use GPT-o3
- +Quality matters more than cost
- +You prefer a managed API without infrastructure overhead
- +Your use case involves advanced reasoning, agentic tasks, research
Cost Analysis
At current pricing, Jamba 1.5 Mini is 16.7x more affordable than GPT-o3. For a typical enterprise workload processing 100M tokens per month:
Jamba 1.5 Mini monthly cost
$30
100M tokens/mo (50/50 in/out)
GPT-o3 monthly cost
$500
100M tokens/mo (50/50 in/out)
The Verdict
Jamba 1.5 Mini wins our head-to-head comparison with 4 out of 5 category wins. It's the stronger choice for cost-effective long-context, summarization, though GPT-o3 holds an edge in advanced reasoning, agentic tasks, research.
Last compared: April 2026 · Data sourced from public benchmarks and official pricing pages