Model Comparison

GPT-5.1 Codex vs Jamba 1.5 LargeWhich is better in 2026?

Comparing GPT-5.1 Codex and Jamba 1.5 Large across benchmarks, pricing, and capabilities.

Verdict: GPT-5.1 Codex vs Jamba 1.5 Large — which is better?

GPT-5.1 Codex (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 Codex 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 Codex if…

  • 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
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Performance Benchmarks

Comparative analysis across standard metrics

No common benchmarks found

GPT-5.1 Codex and Jamba 1.5 Largedon't have any common benchmark datasets to compare. They may have been evaluated on different testing suites.

Arena Performance

Human preference votes

Pricing Analysis

Price comparison per million tokens

GPT-5.1 Codex costs less

For input processing, GPT-5.1 Codex ($1.25/1M tokens) is 1.6x cheaper than Jamba 1.5 Large ($2.00/1M tokens).

For output processing, GPT-5.1 Codex ($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 Codex.*

* Using a 3:1 ratio of input to output tokens

Lowest available price from all providers
Mon Jun 15 2026 • llm-stats.com
OpenAI
GPT-5.1 Codex
Input tokens$1.25
Output tokens$10.00
Best providerOpenAI
AI21 Labs
Jamba 1.5 Large
Input tokens$2.00
Output tokens$8.00
Best providerAWS Bedrock
Notice missing or incorrect data?Start an Issue→

Context Window

Maximum input and output token capacity

GPT-5.1 Codex 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 Codex is limited to 128,000 tokens.

OpenAI
GPT-5.1 Codex
Input400,000 tokens
Output128,000 tokens
AI21 Labs
Jamba 1.5 Large
Input256,000 tokens
Output256,000 tokens
Mon Jun 15 2026 • llm-stats.com

Input Capabilities

Supported data types and modalities

GPT-5.1 Codex supports multimodal inputs, whereas Jamba 1.5 Large does not.

GPT-5.1 Codex can handle both text and other forms of data like images, making it suitable for multimodal applications.

GPT-5.1 Codex

Text
Images
Audio
Video

Jamba 1.5 Large

Text
Images
Audio
Video

License

Usage and distribution terms

GPT-5.1 Codex 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.

GPT-5.1 Codex

Proprietary

Closed source

Jamba 1.5 Large

Jamba Open Model License

Open weights

Release Timeline

When each model was launched

GPT-5.1 Codex was released on 2025-11-19, while Jamba 1.5 Large was released on 2024-08-22.

GPT-5.1 Codex is 15 months newer than Jamba 1.5 Large.

GPT-5.1 Codex

Nov 19, 2025

6 months ago

1.2yr newer
Jamba 1.5 Large

Aug 22, 2024

1.8 years ago

Knowledge Cutoff

When training data ends

GPT-5.1 Codex has a knowledge cutoff of 2024-09-30, while Jamba 1.5 Large has a cutoff of 2024-03-05.

GPT-5.1 Codex has more recent training data (up to 2024-09-30), making it potentially better informed about events through that date compared to Jamba 1.5 Large (2024-03-05).

GPT-5.1 Codex

Sep 2024

6 mo newer
Jamba 1.5 Large

Mar 2024

Provider Availability

GPT-5.1 Codex is available from OpenAI. Jamba 1.5 Large is available from Bedrock, Google.

GPT-5.1 Codex

openai logo
OpenAI
Input Price:Input: $1.25/1MOutput Price:Output: $10.00/1M

Jamba 1.5 Large

bedrock logo
AWS Bedrock
Input Price:Input: $2.00/1MOutput Price:Output: $8.00/1M
google logo
Google
Input Price:Input: $2.00/1MOutput Price:Output: $8.00/1M
* Prices shown are per million tokens

Outputs Comparison

Notice missing or incorrect data?Start an Issue discussion→

Key Takeaways

OpenAI
Larger context window (400,000 tokens)
Supports multimodal inputs
Less expensive input tokens
AI21 Labs
Less expensive output tokens
Has open weights

Detailed Comparison

AI Model Comparison Table
Feature
OpenAI
GPT-5.1 Codex
AI21 Labs
Jamba 1.5 Large

FAQ

Common questions about GPT-5.1 Codex vs Jamba 1.5 Large.

Which is better, GPT-5.1 Codex or Jamba 1.5 Large?

GPT-5.1 Codex (OpenAI) and Jamba 1.5 Large (AI21 Labs) each have strengths in different areas. Compare their benchmark scores, pricing, context windows, and capabilities above to determine which fits your needs.

How does GPT-5.1 Codex compare to Jamba 1.5 Large in benchmarks?

GPT-5.1 Codex scores SWE-Bench Verified: 73.7%, SWE-Lancer: 66.3%, Terminal-Bench 2.0: 52.8%. Jamba 1.5 Large scores ARC-C: 93.0%, GSM8k: 87.0%, MMLU: 81.2%, Arena Hard: 65.4%, TruthfulQA: 58.3%.

Is GPT-5.1 Codex cheaper than Jamba 1.5 Large?

GPT-5.1 Codex is 1.6x cheaper for input tokens. GPT-5.1 Codex costs $1.25/M input and $10.00/M output via openai. Jamba 1.5 Large costs $2.00/M input and $8.00/M output via bedrock.

What are the context window sizes for GPT-5.1 Codex and Jamba 1.5 Large?

GPT-5.1 Codex supports 400K 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 GPT-5.1 Codex and Jamba 1.5 Large?

Key differences include context window (400K vs 256K), input pricing ($1.25 vs $2.00/M), multimodal support (yes vs no), licensing (Proprietary vs Jamba Open Model License). See the full comparison above for benchmark-by-benchmark results.

Who makes GPT-5.1 Codex and Jamba 1.5 Large?

GPT-5.1 Codex is developed by OpenAI and Jamba 1.5 Large is developed by AI21 Labs.

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