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GPT-5.1 Codex vs GPT-6 Rosalind

Comparing GPT-5.1 Codex and GPT-6 Rosalind across benchmarks, pricing, and capabilities.

OpenAI · OpenAI · Updated for 2026

Which is better?

GPT-5.1 Codex and GPT-6 Rosalind trade strengths across price, capabilities, and technical limits. The better choice depends on the workload.

On price, GPT-5.1 Codex is roughly 8.7x cheaper per token on a blended 3:1 input/output basis, which adds up quickly at production volume.

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

Choose GPT-5.1 Codex

  • cost matters — it's about 8.7x cheaper per token

Choose GPT-6 Rosalind

  • you want the most recent training data — it shipped Oct 2026

At a glance

The differences that matter most.

GPT-5.1 Codex
OpenAI
GPT-6 Rosalind
OpenAI
Benchmark wins
—
—
Input price
$1.25 / M
$15.00 / M
Output price
$10.00 / M
$75.00 / M
Context window
400,000
—

Individual benchmarks

3 reported for GPT-5.1 Codex · 0 for GPT-6 Rosalind

No common benchmarks found

GPT-5.1 Codex and GPT-6 Rosalinddon'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

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 12.0x cheaper than GPT-6 Rosalind ($15.00/1M tokens).

For output processing, GPT-5.1 Codex ($10.00/1M tokens) is 7.5x cheaper than GPT-6 Rosalind ($75.00/1M tokens).

In conclusion, GPT-6 Rosalind 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 Nov 02 2026 • llm-stats.com
OpenAI
GPT-5.1 Codex
Input tokens$1.25
Output tokens$10.00
Best providerOpenAI
OpenAI
GPT-6 Rosalind
Input tokens$15.00
Output tokens$75.00
Best providerOpenAI
Notice missing or incorrect data?

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
OpenAI
GPT-6 Rosalind
Input- tokens
Output- tokens
Mon Nov 02 2026 • llm-stats.com

Input capabilities

Documented input modalities across available providers

Both GPT-5.1 Codex and GPT-6 Rosalind 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

GPT-6 Rosalind

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

GPT-6 Rosalind

Proprietary

Closed source

Release Timeline

When each model was launched

GPT-5.1 Codex was released on 2025-11-19, while GPT-6 Rosalind was released on 2026-10-30.

GPT-6 Rosalind is 12 months newer than GPT-5.1 Codex.

GPT-5.1 Codex

Nov 19, 2025

11 months ago

GPT-6 Rosalind

Oct 30, 2026

2 days ago

11mo newer

Knowledge Cutoff

When training data ends

GPT-5.1 Codex has a documented knowledge cutoff of 2024-09-30, while GPT-6 Rosalind'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 GPT-6 Rosalind's cutoff date.

GPT-5.1 Codex

Sep 2024

GPT-6 Rosalind

—

Provider Availability

GPT-5.1 Codex is available from OpenAI. GPT-6 Rosalind is available from OpenAI.

GPT-5.1 Codex

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

GPT-6 Rosalind

openai logo
OpenAI
Input Price:Input: $15.00/1MOutput Price:Output: $75.00/1M
* Prices shown are per million tokens

Outputs Comparison

Notice missing or incorrect data?

Judge for yourself.

Run your own prompts against GPT-5.1 Codex and GPT-6 Rosalind side-by-side, then vote on the output you prefer.

GPT-5.1 Codex
✓ Preferred
GPT-6 Rosalind
Open in Playground

FAQ

Common questions about GPT-5.1 Codex vs GPT-6 Rosalind.

Which is better, GPT-5.1 Codex or GPT-6 Rosalind?

GPT-5.1 Codex (OpenAI) and GPT-6 Rosalind (OpenAI) 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 GPT-6 Rosalind in benchmarks?

GPT-5.1 Codex scores SWE-Bench Verified: 73.7%, SWE-Lancer: 66.3%, Terminal-Bench 2.0: 52.8%.

Is GPT-5.1 Codex cheaper than GPT-6 Rosalind?

GPT-5.1 Codex is 12.0x cheaper for input tokens. GPT-5.1 Codex costs $1.25/M input and $10.00/M output via openai. GPT-6 Rosalind costs $15.00/M input and $75.00/M output via openai.

What are the context window sizes for GPT-5.1 Codex and GPT-6 Rosalind?

GPT-5.1 Codex supports 400K tokens and GPT-6 Rosalind 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 GPT-6 Rosalind?

Key differences include input pricing ($1.25 vs $15.00/M). See the full comparison above for benchmark-by-benchmark results.

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