Model Comparison

Claude Opus 4.1 vs GPT-5.1 Medium

GPT-5.1 Medium significantly outperforms across most benchmarks. GPT-5.1 Medium is 8.7x cheaper per token.

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Performance Benchmarks

Comparative analysis across standard metrics

1 benchmarks

Claude Opus 4.1 outperforms in 0 benchmarks, while GPT-5.1 Medium is better at 1 benchmark (AIME 2025).

GPT-5.1 Medium significantly outperforms across most benchmarks.

Thu Apr 16 2026 • llm-stats.com

Arena Performance

Human preference votes

Pricing Analysis

Price comparison per million tokens

GPT-5.1 Medium costs less

For input processing, Claude Opus 4.1 ($15.00/1M tokens) is 12.0x more expensive than GPT-5.1 Medium ($1.25/1M tokens).

For output processing, Claude Opus 4.1 ($75.00/1M tokens) is 7.5x more expensive than GPT-5.1 Medium ($10.00/1M tokens).

In conclusion, Claude Opus 4.1 is more expensive than GPT-5.1 Medium.*

* 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 Opus 4.1
Input tokens$15.00
Output tokens$75.00
Best providerAnthropic
OpenAI
GPT-5.1 Medium
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 Medium accepts 400,000 input tokens compared to Claude Opus 4.1's 200,000 tokens. GPT-5.1 Medium can generate longer responses up to 128,000 tokens, while Claude Opus 4.1 is limited to 32,000 tokens.

Anthropic
Claude Opus 4.1
Input200,000 tokens
Output32,000 tokens
OpenAI
GPT-5.1 Medium
Input400,000 tokens
Output128,000 tokens
Thu Apr 16 2026 • llm-stats.com

Input Capabilities

Supported data types and modalities

Both Claude Opus 4.1 and GPT-5.1 Medium support multimodal inputs.

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

Claude Opus 4.1

Text
Images
Audio
Video

GPT-5.1 Medium

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 Opus 4.1

Proprietary

Closed source

GPT-5.1 Medium

Proprietary

Closed source

Release Timeline

When each model was launched

Claude Opus 4.1 was released on 2025-08-05, while GPT-5.1 Medium was released on 2025-11-12.

GPT-5.1 Medium is 3 months newer than Claude Opus 4.1.

Claude Opus 4.1

Aug 5, 2025

8 months ago

GPT-5.1 Medium

Nov 12, 2025

5 months ago

3mo 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 Opus 4.1 is available from Anthropic, Bedrock, Google. GPT-5.1 Medium is available from OpenAI.

Claude Opus 4.1

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 Medium

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

Outputs Comparison

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Key Takeaways

Anthropic
OpenAI
Larger context window (400,000 tokens)
Less expensive input tokens
Less expensive output tokens
Higher AIME 2025 score (98.4% vs 78.0%)

Detailed Comparison

AI Model Comparison Table
Feature
Anthropic
Claude Opus 4.1
OpenAI
GPT-5.1 Medium

FAQ

Common questions about Claude Opus 4.1 vs GPT-5.1 Medium

GPT-5.1 Medium significantly outperforms across most benchmarks. Claude Opus 4.1 is made by Anthropic and GPT-5.1 Medium is made by OpenAI. The best choice depends on your use case — compare their benchmark scores, pricing, and capabilities above.
Claude Opus 4.1 scores MMMLU: 89.5%, TAU-bench Retail: 82.4%, GPQA: 80.9%, AIME 2025: 78.0%, MMMU (validation): 77.1%. GPT-5.1 Medium scores AIME 2025: 98.4%.
GPT-5.1 Medium is 12.0x cheaper for input tokens. Claude Opus 4.1 costs $15.00/M input and $75.00/M output via anthropic. GPT-5.1 Medium costs $1.25/M input and $10.00/M output via openai.
Claude Opus 4.1 supports 200K tokens and GPT-5.1 Medium 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 Opus 4.1 is developed by Anthropic and GPT-5.1 Medium is developed by OpenAI.