Model Comparison

Claude 3 Opus vs GPT-5.1 Codex High

Comparing Claude 3 Opus and GPT-5.1 Codex High across benchmarks, pricing, and capabilities.

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Performance Benchmarks

Comparative analysis across standard metrics

No common benchmarks found

Claude 3 Opus and GPT-5.1 Codex High don'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 High costs less

For input processing, Claude 3 Opus ($15.00/1M tokens) is 12.0x more expensive than GPT-5.1 Codex High ($1.25/1M tokens).

For output processing, Claude 3 Opus ($75.00/1M tokens) is 7.5x more expensive than GPT-5.1 Codex High ($10.00/1M tokens).

In conclusion, Claude 3 Opus is more expensive than GPT-5.1 Codex High.*

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

Lowest available price from all providers
Thu Apr 16 2026 • llm-stats.com
Anthropic
Claude 3 Opus
Input tokens$15.00
Output tokens$75.00
Best providerAnthropic
OpenAI
GPT-5.1 Codex High
Input tokens$1.25
Output tokens$10.00
Best providerOpenAI
Notice missing or incorrect data?Start an Issue→

Context Window

Maximum input and output token capacity

GPT-5.1 Codex High accepts 400,000 input tokens compared to Claude 3 Opus's 200,000 tokens. Claude 3 Opus can generate longer responses up to 200,000 tokens, while GPT-5.1 Codex High is limited to 128,000 tokens.

Anthropic
Claude 3 Opus
Input200,000 tokens
Output200,000 tokens
OpenAI
GPT-5.1 Codex High
Input400,000 tokens
Output128,000 tokens
Thu Apr 16 2026 • llm-stats.com

Input Capabilities

Supported data types and modalities

Both Claude 3 Opus and GPT-5.1 Codex High support multimodal inputs.

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

Claude 3 Opus

Text
Images
Audio
Video

GPT-5.1 Codex High

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.

Claude 3 Opus

Proprietary

Closed source

GPT-5.1 Codex High

Proprietary

Closed source

Release Timeline

When each model was launched

Claude 3 Opus was released on 2024-02-29, while GPT-5.1 Codex High was released on 2025-11-12.

GPT-5.1 Codex High is 21 months newer than Claude 3 Opus.

Claude 3 Opus

Feb 29, 2024

2.1 years ago

GPT-5.1 Codex High

Nov 12, 2025

5 months ago

1.7yr newer

Knowledge Cutoff

When training data ends

Neither model specifies a knowledge cutoff date.

Unable to compare the recency of their training data.

No cutoff dates available

Provider Availability

Claude 3 Opus is available from Anthropic, Bedrock, Google. GPT-5.1 Codex High is available from OpenAI.

Claude 3 Opus

anthropic logo
Anthropic
Input Price:Input: $15.00/1MOutput Price:Output: $75.00/1M
bedrock logo
AWS Bedrock
Input Price:Input: $15.00/1MOutput Price:Output: $75.00/1M
google logo
Google
Input Price:Input: $15.00/1MOutput Price:Output: $75.00/1M

GPT-5.1 Codex High

openai logo
OpenAI
Input Price:Input: $1.25/1MOutput Price:Output: $10.00/1M
* Prices shown are per million tokens

Outputs Comparison

Notice missing or incorrect data?Start an Issue discussion→

Key Takeaways

Anthropic
OpenAI
Larger context window (400,000 tokens)
Less expensive input tokens
Less expensive output tokens

Detailed Comparison

AI Model Comparison Table
Feature
Anthropic
Claude 3 Opus
OpenAI
GPT-5.1 Codex High

FAQ

Common questions about Claude 3 Opus vs GPT-5.1 Codex High

Claude 3 Opus (Anthropic) and GPT-5.1 Codex High (OpenAI) each have strengths in different areas. Compare their benchmark scores, pricing, context windows, and capabilities above to determine which fits your needs.
Claude 3 Opus scores ARC-C: 96.4%, HellaSwag: 95.4%, GSM8k: 95.0%, MGSM: 90.7%, BIG-Bench Hard: 86.8%. GPT-5.1 Codex High scores AIME 2025: 96.7%.
GPT-5.1 Codex High is 12.0x cheaper for input tokens. Claude 3 Opus costs $15.00/M input and $75.00/M output via anthropic. GPT-5.1 Codex High costs $1.25/M input and $10.00/M output via openai.
Claude 3 Opus supports 200K tokens and GPT-5.1 Codex High supports 400K tokens. A larger context window lets you process longer documents, conversations, or codebases in a single request.
Key differences include context window (200K vs 400K), input pricing ($15.00 vs $1.25/M). See the full comparison above for benchmark-by-benchmark results.
Claude 3 Opus is developed by Anthropic and GPT-5.1 Codex High is developed by OpenAI.