Model Comparison

Claude Opus 4.5 vs GPT-5.5 ProWhich is better in 2026?

Comparing Claude Opus 4.5 and GPT-5.5 Pro across benchmarks, pricing, and capabilities.

Verdict: Claude Opus 4.5 vs GPT-5.5 Pro — which is better?

Claude Opus 4.5 (by Anthropic) and GPT-5.5 Pro (by OpenAI) are two of the AI models people compare most. Here is how they stack up on benchmarks, price and capabilities, and which one to pick in 2026.

On price, Claude Opus 4.5 is roughly 6.8x cheaper per token on a blended 3:1 input/output basis, which adds up quickly at production volume.

GPT-5.5 Pro also accepts a larger context window (1,050,000 input tokens), making it the stronger choice for long documents and large codebases.

Choose Claude Opus 4.5 if…

  • cost matters — it's about 6.8x cheaper per token

Choose GPT-5.5 Pro if…

  • you process long inputs — it offers a 1,050,000 token context window
  • you want the most recent training data — it shipped Apr 2026

Performance Benchmarks

Comparative analysis across standard metrics

No common benchmarks found

Claude Opus 4.5 and GPT-5.5 Prodon'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

Claude Opus 4.5 costs less

For input processing, Claude Opus 4.5 ($5.00/1M tokens) is 6.0x cheaper than GPT-5.5 Pro ($30.00/1M tokens).

For output processing, Claude Opus 4.5 ($25.00/1M tokens) is 7.2x cheaper than GPT-5.5 Pro ($180.00/1M tokens).

In conclusion, GPT-5.5 Pro is more expensive than Claude Opus 4.5.*

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

Lowest available price from all providers
Fri Jul 17 2026 • llm-stats.com
Anthropic
Claude Opus 4.5
Input tokens$5.00
Output tokens$25.00
Best providerAnthropic
OpenAI
GPT-5.5 Pro
Input tokens$30.00
Output tokens$180.00
Best providerOpenAI
Notice missing or incorrect data?Start an Issue→

Context Window

Maximum input and output token capacity

GPT-5.5 Pro accepts 1,050,000 input tokens compared to Claude Opus 4.5's 200,000 tokens. GPT-5.5 Pro can generate longer responses up to 128,000 tokens, while Claude Opus 4.5 is limited to 64,000 tokens.

Anthropic
Claude Opus 4.5
Input200,000 tokens
Output64,000 tokens
OpenAI
GPT-5.5 Pro
Input1,050,000 tokens
Output128,000 tokens
Fri Jul 17 2026 • llm-stats.com

Input Capabilities

Supported data types and modalities

Both Claude Opus 4.5 and GPT-5.5 Pro support multimodal inputs.

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

Claude Opus 4.5

Text
Images
Audio
Video

GPT-5.5 Pro

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 4.5

Proprietary

Closed source

GPT-5.5 Pro

Proprietary

Closed source

Release Timeline

When each model was launched

Claude Opus 4.5 was released on 2025-11-24, while GPT-5.5 Pro was released on 2026-04-23.

GPT-5.5 Pro is 5 months newer than Claude Opus 4.5.

Claude Opus 4.5

Nov 24, 2025

7 months ago

GPT-5.5 Pro

Apr 23, 2026

2 months ago

5mo newer

Knowledge Cutoff

When training data ends

Claude Opus 4.5 has a knowledge cutoff of 2025-03-31, while GPT-5.5 Pro has a cutoff of 2025-12-01.

GPT-5.5 Pro has more recent training data (up to 2025-12-01), making it potentially better informed about events through that date compared to Claude Opus 4.5 (2025-03-31).

Claude Opus 4.5

Mar 2025

GPT-5.5 Pro

Dec 2025

9 mo newer

Provider Availability

Claude Opus 4.5 is available from Anthropic. GPT-5.5 Pro is available from OpenAI.

Claude Opus 4.5

anthropic logo
Anthropic
Input Price:Input: $5.00/1MOutput Price:Output: $25.00/1M

GPT-5.5 Pro

openai logo
OpenAI
Input Price:Input: $30.00/1MOutput Price:Output: $180.00/1M
* Prices shown are per million tokens

Outputs Comparison

Notice missing or incorrect data?Start an Issue discussion→

Key Takeaways

Anthropic
Less expensive input tokens
Less expensive output tokens
OpenAI
Larger context window (1,050,000 tokens)

Detailed Comparison

Interactive Arena

Judge for yourself.

Run your own prompts against Claude Opus 4.5 and GPT-5.5 Pro side-by-side, then vote on the output you prefer.

Claude Opus 4.5
✓ Preferred
GPT-5.5 Pro
Open in Playground
AI Model Comparison Table
Feature
Anthropic
Claude Opus 4.5
OpenAI
GPT-5.5 Pro

FAQ

Common questions about Claude Opus 4.5 vs GPT-5.5 Pro.

Which is better, Claude Opus 4.5 or GPT-5.5 Pro?

Claude Opus 4.5 (Anthropic) and GPT-5.5 Pro (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 Claude Opus 4.5 compare to GPT-5.5 Pro in benchmarks?

Claude Opus 4.5 scores Tau2 Telecom: 98.2%, MMMLU: 90.8%, Tau2 Retail: 88.9%, GPQA: 87.0%, SWE-Bench Verified: 80.9%. GPT-5.5 Pro scores BrowseComp: 90.1%, GDPval-MM: 82.3%, Humanity's Last Exam: 57.2%, FrontierMath: 39.6%, GeneBench: 33.2%.

Is Claude Opus 4.5 cheaper than GPT-5.5 Pro?

Claude Opus 4.5 is 6.0x cheaper for input tokens. Claude Opus 4.5 costs $5.00/M input and $25.00/M output via anthropic. GPT-5.5 Pro costs $30.00/M input and $180.00/M output via openai.

What are the context window sizes for Claude Opus 4.5 and GPT-5.5 Pro?

Claude Opus 4.5 supports 200K tokens and GPT-5.5 Pro supports 1.1M tokens. A larger context window lets you process longer documents, conversations, or codebases in a single request.

What are the main differences between Claude Opus 4.5 and GPT-5.5 Pro?

Key differences include context window (200K vs 1.1M), input pricing ($5.00 vs $30.00/M). See the full comparison above for benchmark-by-benchmark results.

Who makes Claude Opus 4.5 and GPT-5.5 Pro?

Claude Opus 4.5 is developed by Anthropic and GPT-5.5 Pro is developed by OpenAI.

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