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GPT-5.1 Codex vs Grok-1.5V

GPT-5.1 Codex leads the LLM Stats Score 29.5 to -0.7.

OpenAI · xAI · Updated for 2026

Which is better?

GPT-5.1 Codex leads the overall LLM Stats Score 29.5 to -0.7, ranking #118 overall.

Based on current LLM Stats indexes, shared benchmarks, pricing, and model metadata for 2026.

Choose GPT-5.1 Codex

  • overall performance matters — it scores 29.5 and ranks #118 on LLM Stats
  • your work emphasizes reasoning — it leads those capability indexes
  • you want the most recent training data — it shipped Nov 2025

Choose Grok-1.5V

  • you are already invested in the xAI ecosystem

At a glance

The differences that matter most.

GPT-5.1 Codex
OpenAI
Grok-1.5V
xAI
Core performance indexes
LLM Stats Score
29.5
#118
-0.7
#320
Reasoning
29.6
#111
0.0
#306
Cost, coverage & limits
Benchmark wins
—
—
Input price
$1.25 / M
— / M
Output price
$10.00 / M
— / M
Context window
400,000
—

Individual benchmarks

3 reported for GPT-5.1 Codex · 7 for Grok-1.5V

No common benchmarks found

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

Human preference

Blind head-to-head votes and playground preference scores

Context Window

Maximum input and output token capacity

Only GPT-5.1 Codex specifies input context (400,000 tokens). Only GPT-5.1 Codex specifies output context (128,000 tokens).

OpenAI
GPT-5.1 Codex
Input400,000 tokens
Output128,000 tokens
xAI
Grok-1.5V
Input- tokens
Output- tokens
Sun Sep 06 2026 • llm-stats.com

Input capabilities

Documented input modalities across available providers

Both GPT-5.1 Codex and Grok-1.5V support multimodal inputs.

They are both capable of processing various types of data, offering versatility in application.

GPT-5.1 Codex

Text
Images
Audio
Video

Grok-1.5V

Text
Images
Audio
Video

License

Usage and distribution terms

Both models are licensed under proprietary licenses.

Both models have usage restrictions defined by their respective organizations.

GPT-5.1 Codex

Proprietary

Closed source

Grok-1.5V

Proprietary

Closed source

Release Timeline

When each model was launched

GPT-5.1 Codex was released on 2025-11-19, while Grok-1.5V was released on 2024-04-12.

GPT-5.1 Codex is 20 months newer than Grok-1.5V.

GPT-5.1 Codex

Nov 19, 2025

9 months ago

1.6yr newer
Grok-1.5V

Apr 12, 2024

2.4 years ago

Knowledge Cutoff

When training data ends

GPT-5.1 Codex has a documented knowledge cutoff of 2024-09-30, while Grok-1.5V's cutoff date is not specified.

We can confirm GPT-5.1 Codex's training data extends to 2024-09-30, but cannot make a direct comparison without Grok-1.5V's cutoff date.

GPT-5.1 Codex

Sep 2024

Grok-1.5V

—

Outputs Comparison

Notice missing or incorrect data?Start an Issue discussion→

Judge for yourself.

Run your own prompts against GPT-5.1 Codex and Grok-1.5V side-by-side, then vote on the output you prefer.

GPT-5.1 Codex
✓ Preferred
Grok-1.5V
Open in Playground

FAQ

Common questions about GPT-5.1 Codex vs Grok-1.5V.

Which is better, GPT-5.1 Codex or Grok-1.5V?

GPT-5.1 Codex leads the LLM Stats Score 29.5 to -0.7. GPT-5.1 Codex is made by OpenAI and Grok-1.5V is made by xAI. The best choice depends on your use case — compare their capability indexes, individual benchmarks, pricing, and limits above.

How does GPT-5.1 Codex compare to Grok-1.5V in benchmarks?

GPT-5.1 Codex scores SWE-Bench Verified: 73.7%, SWE-Lancer: 66.3%, Terminal-Bench 2.0: 52.8%. Grok-1.5V scores AI2D: 88.3%, DocVQA: 85.6%, TextVQA: 78.1%, ChartQA: 76.1%, RealWorldQA: 68.7%.

What are the context window sizes for GPT-5.1 Codex and Grok-1.5V?

GPT-5.1 Codex supports 400K tokens and Grok-1.5V supports an unknown number of 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 Grok-1.5V?

Key differences include LLM Stats Score (29.5 vs -0.7). See the full comparison above for benchmark-by-benchmark results.

Who makes GPT-5.1 Codex and Grok-1.5V?

GPT-5.1 Codex is developed by OpenAI and Grok-1.5V is developed by xAI.

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