Model Comparison

Grok-1.5 vs Jamba 1.5 LargeWhich is better in 2026?

Both models are evenly matched across the benchmarks.

Verdict: Grok-1.5 vs Jamba 1.5 Large — which is better?

Grok-1.5 (by xAI) 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.

Grok-1.5 outperforms in 2 benchmarks (GSM8k, MMLU), while Jamba 1.5 Large is better at 2 benchmarks (GPQA, MMLU-Pro). Both models are evenly matched across the benchmarks.

Choose Grok-1.5 if…

  • you are already invested in the xAI ecosystem

Choose Jamba 1.5 Large if…

  • you want the most recent training data — it shipped Aug 2024
  • you need open weights you can self-host or fine-tune
Want to compare interactively?Try the playground

Performance Benchmarks

Comparative analysis across standard metrics

4 benchmarks

Grok-1.5 outperforms in 2 benchmarks (GSM8k, MMLU), while Jamba 1.5 Large is better at 2 benchmarks (GPQA, MMLU-Pro).

Both models are evenly matched across the benchmarks.

Wed Jun 17 2026 • llm-stats.com

Arena Performance

Human preference votes

Context Window

Maximum input and output token capacity

Only Jamba 1.5 Large specifies input context (256,000 tokens). Only Jamba 1.5 Large specifies output context (256,000 tokens).

xAI
Grok-1.5
Input- tokens
Output- tokens
AI21 Labs
Jamba 1.5 Large
Input256,000 tokens
Output256,000 tokens
Wed Jun 17 2026 • llm-stats.com

License

Usage and distribution terms

Grok-1.5 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.

Grok-1.5

Proprietary

Closed source

Jamba 1.5 Large

Jamba Open Model License

Open weights

Release Timeline

When each model was launched

Grok-1.5 was released on 2024-03-28, while Jamba 1.5 Large was released on 2024-08-22.

Jamba 1.5 Large is 5 months newer than Grok-1.5.

Grok-1.5

Mar 28, 2024

2.2 years ago

Jamba 1.5 Large

Aug 22, 2024

1.8 years ago

4mo newer

Knowledge Cutoff

When training data ends

Jamba 1.5 Large has a documented knowledge cutoff of 2024-03-05, while Grok-1.5'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 Grok-1.5's cutoff date.

Grok-1.5

—

Jamba 1.5 Large

Mar 2024

Outputs Comparison

Notice missing or incorrect data?Start an Issue discussion→

Key Takeaways

xAI
Higher GSM8k score (90.0% vs 87.0%)
Higher MMLU score (81.3% vs 81.2%)
AI21 Labs
Larger context window (256,000 tokens)
Has open weights
Higher GPQA score (36.9% vs 35.9%)
Higher MMLU-Pro score (53.5% vs 51.0%)

Detailed Comparison

AI Model Comparison Table
Feature
xAI
Grok-1.5
AI21 Labs
Jamba 1.5 Large

FAQ

Common questions about Grok-1.5 vs Jamba 1.5 Large.

Which is better, Grok-1.5 or Jamba 1.5 Large?

Both models are evenly matched across the benchmarks. Grok-1.5 is made by xAI and Jamba 1.5 Large is made by AI21 Labs. The best choice depends on your use case — compare their benchmark scores, pricing, and capabilities above.

How does Grok-1.5 compare to Jamba 1.5 Large in benchmarks?

Grok-1.5 scores GSM8k: 90.0%, DocVQA: 85.6%, MMLU: 81.3%, HumanEval: 74.1%, MMMU: 53.6%. Jamba 1.5 Large scores ARC-C: 93.0%, GSM8k: 87.0%, MMLU: 81.2%, Arena Hard: 65.4%, TruthfulQA: 58.3%.

What are the context window sizes for Grok-1.5 and Jamba 1.5 Large?

Grok-1.5 supports an unknown number of tokens and Jamba 1.5 Large supports 256K tokens. A larger context window lets you process longer documents, conversations, or codebases in a single request.

What are the main differences between Grok-1.5 and Jamba 1.5 Large?

Key differences include licensing (Proprietary vs Jamba Open Model License). See the full comparison above for benchmark-by-benchmark results.

Who makes Grok-1.5 and Jamba 1.5 Large?

Grok-1.5 is developed by xAI and Jamba 1.5 Large is developed by AI21 Labs.

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