Model Comparison
GPT-5.1 Thinking vs Jamba 1.5 LargeWhich is better in 2026?
GPT-5.1 Thinking significantly outperforms across most benchmarks. GPT-5.1 Thinking is 1.0x cheaper per token.
Verdict: GPT-5.1 Thinking vs Jamba 1.5 Large — which is better?
GPT-5.1 Thinking (by OpenAI) and Jamba 1.5 Large (by AI21 Labs) are two of the AI models people compare most. Here is how they stack up on benchmarks, price and capabilities, and which one to pick in 2026.
GPT-5.1 Thinking outperforms in 1 benchmarks (GPQA), while Jamba 1.5 Large is better at 0 benchmarks. GPT-5.1 Thinking significantly outperforms across most benchmarks.
GPT-5.1 Thinking also accepts a larger context window (400,000 input tokens), making it the stronger choice for long documents and large codebases.
Choose GPT-5.1 Thinking if…
- you want the strongest raw capability — it leads on 1 of 1 shared benchmarks
- you process long inputs — it offers a 400,000 token context window
- you want the most recent training data — it shipped Nov 2025
Choose Jamba 1.5 Large if…
- you need open weights you can self-host or fine-tune
Performance Benchmarks
Comparative analysis across standard metrics
GPT-5.1 Thinking outperforms in 1 benchmarks (GPQA), while Jamba 1.5 Large is better at 0 benchmarks.
GPT-5.1 Thinking significantly outperforms across most benchmarks.
Arena Performance
Human preference votes
Pricing Analysis
Price comparison per million tokens
For input processing, GPT-5.1 Thinking ($1.25/1M tokens) is 1.6x cheaper than Jamba 1.5 Large ($2.00/1M tokens).
For output processing, GPT-5.1 Thinking ($10.00/1M tokens) is 1.3x more expensive than Jamba 1.5 Large ($8.00/1M tokens).
In conclusion, Jamba 1.5 Large is more expensive than GPT-5.1 Thinking.*
* Using a 3:1 ratio of input to output tokens
Context Window
Maximum input and output token capacity
GPT-5.1 Thinking accepts 400,000 input tokens compared to Jamba 1.5 Large's 256,000 tokens. Jamba 1.5 Large can generate longer responses up to 256,000 tokens, while GPT-5.1 Thinking is limited to 128,000 tokens.
Input Capabilities
Supported data types and modalities
GPT-5.1 Thinking supports multimodal inputs, whereas Jamba 1.5 Large does not.
GPT-5.1 Thinking can handle both text and other forms of data like images, making it suitable for multimodal applications.
GPT-5.1 Thinking
Jamba 1.5 Large
License
Usage and distribution terms
GPT-5.1 Thinking is licensed under a proprietary license, while Jamba 1.5 Large uses Jamba Open Model License.
License differences may affect how you can use these models in commercial or open-source projects.
Proprietary
Closed source
Jamba Open Model License
Open weights
Release Timeline
When each model was launched
GPT-5.1 Thinking was released on 2025-11-12, while Jamba 1.5 Large was released on 2024-08-22.
GPT-5.1 Thinking is 15 months newer than Jamba 1.5 Large.
Nov 12, 2025
7 months ago
1.2yr newerAug 22, 2024
1.8 years ago
Knowledge Cutoff
When training data ends
Jamba 1.5 Large has a documented knowledge cutoff of 2024-03-05, while GPT-5.1 Thinking's cutoff date is not specified.
We can confirm Jamba 1.5 Large's training data extends to 2024-03-05, but cannot make a direct comparison without GPT-5.1 Thinking's cutoff date.
—
Mar 2024
Provider Availability
GPT-5.1 Thinking is available from OpenAI. Jamba 1.5 Large is available from Bedrock, Google.
GPT-5.1 Thinking
Jamba 1.5 Large
Outputs Comparison
Key Takeaways
Jamba 1.5 Large
View detailsAI21 Labs
Detailed Comparison
Interactive Arena
Judge for yourself.
Run your own prompts against GPT-5.1 Thinking and Jamba 1.5 Large side-by-side, then vote on the output you prefer.
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FAQ
Common questions about GPT-5.1 Thinking vs Jamba 1.5 Large.