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GPT-5.1 Codex vs Grok 4.6

Comparing GPT-5.1 Codex and Grok 4.6 across benchmarks, pricing, and capabilities.

OpenAI · xAI · Updated for 2026

Which is better?

GPT-5.1 Codex and Grok 4.6 trade strengths across price, capabilities, and technical limits. The better choice depends on the workload.

On price, Grok 4.6 is roughly 1.1x cheaper per token on a blended 3:1 input/output basis, which adds up quickly at production volume.

Grok 4.6 also accepts a larger context window (500,000 input tokens), making it the stronger choice for long documents and large codebases.

Based on current benchmark, pricing, and model metadata for 2026.

Choose GPT-5.1 Codex

  • you want predictable pricing at $1.25/M input and $10.00/M output

Choose Grok 4.6

  • cost matters — it's about 1.1x cheaper per token
  • you process long inputs — it offers a 500,000 token context window
  • you want the most recent training data — it shipped Aug 2026

At a glance

The differences that matter most.

GPT-5.1 Codex
OpenAI
Grok 4.6
xAI
Benchmark wins
—
—
Input price
$1.25 / M
$2.00 / M
Output price
$10.00 / M
$6.00 / M
Context window
400,000
500,000
Released
Nov 2025
Aug 2026
License
Proprietary
Proprietary

Performance Benchmarks

Comparative analysis across standard metrics

No common benchmarks found

GPT-5.1 Codex and Grok 4.6don't have any common benchmark datasets to compare. They may have been evaluated on different testing suites.

Arena Performance

Playground indexes and blind preference scores

Pricing Analysis

Price comparison per million tokens

Grok 4.6 costs less

For input processing, GPT-5.1 Codex ($1.25/1M tokens) is 1.6x cheaper than Grok 4.6 ($2.00/1M tokens).

For output processing, GPT-5.1 Codex ($10.00/1M tokens) is 1.7x more expensive than Grok 4.6 ($6.00/1M tokens).

In conclusion, GPT-5.1 Codex is more expensive than Grok 4.6.*

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

Lowest available price from all providers
Mon Aug 24 2026 • llm-stats.com
OpenAI
GPT-5.1 Codex
Input tokens$1.25
Output tokens$10.00
Best providerOpenAI
xAI
Grok 4.6
Input tokens$2.00
Output tokens$6.00
Best providerxAI
Notice missing or incorrect data?Start an Issue→

Context Window

Maximum input and output token capacity

Grok 4.6 accepts 500,000 input tokens compared to GPT-5.1 Codex's 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 4.6
Input500,000 tokens
Output- tokens
Mon Aug 24 2026 • llm-stats.com

Input Capabilities

Supported data types and modalities

Both GPT-5.1 Codex and Grok 4.6 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 4.6

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 4.6

Proprietary

Closed source

Release Timeline

When each model was launched

GPT-5.1 Codex was released on 2025-11-19, while Grok 4.6 was released on 2026-08-12.

Grok 4.6 is 9 months newer than GPT-5.1 Codex.

GPT-5.1 Codex

Nov 19, 2025

9 months ago

Grok 4.6

Aug 12, 2026

1 weeks ago

8mo newer

Knowledge Cutoff

When training data ends

GPT-5.1 Codex has a knowledge cutoff of 2024-09-30, while Grok 4.6 has a cutoff of 2026-02-01.

Grok 4.6 has more recent training data (up to 2026-02-01), making it potentially better informed about events through that date compared to GPT-5.1 Codex (2024-09-30).

GPT-5.1 Codex

Sep 2024

Grok 4.6

Feb 2026

1.4 yr newer

Provider Availability

GPT-5.1 Codex is available from OpenAI. Grok 4.6 is available from xAI.

GPT-5.1 Codex

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

Grok 4.6

xai logo
xAI
Input Price:Input: $2.00/1MOutput Price:Output: $6.00/1M
* Prices shown are per million tokens

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 4.6 side-by-side, then vote on the output you prefer.

GPT-5.1 Codex
✓ Preferred
Grok 4.6
Open in Playground

FAQ

Common questions about GPT-5.1 Codex vs Grok 4.6.

Which is better, GPT-5.1 Codex or Grok 4.6?

GPT-5.1 Codex (OpenAI) and Grok 4.6 (xAI) 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 Grok 4.6 in benchmarks?

GPT-5.1 Codex scores SWE-Bench Verified: 73.7%, SWE-Lancer: 66.3%, Terminal-Bench 2.0: 52.8%. Grok 4.6 scores CursorBench v3.2: 69.9%, DeepSWE 1.1: 65.9%, FrontierCode: 61.3%, AA-Index: 61.0%, GDPval-AA: 58.4%.

Is GPT-5.1 Codex cheaper than Grok 4.6?

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. Grok 4.6 costs $2.00/M input and $6.00/M output via xai.

What are the context window sizes for GPT-5.1 Codex and Grok 4.6?

GPT-5.1 Codex supports 400K tokens and Grok 4.6 supports 500K 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 4.6?

Key differences include context window (400K vs 500K), input pricing ($1.25 vs $2.00/M). See the full comparison above for benchmark-by-benchmark results.

Who makes GPT-5.1 Codex and Grok 4.6?

GPT-5.1 Codex is developed by OpenAI and Grok 4.6 is developed by xAI.

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