Model Comparison

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

GPT-5.5 significantly outperforms across most benchmarks. Claude Opus 4.5 is 1.1x cheaper per token.

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

Claude Opus 4.5 (by Anthropic) and GPT-5.5 (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.

Claude Opus 4.5 outperforms in 1 benchmarks (Tau2 Telecom), while GPT-5.5 is better at 5 benchmarks (ARC-AGI v2, GPQA, LiveBench, MCP Atlas, Terminal-Bench 2.0). GPT-5.5 significantly outperforms across most benchmarks.

On price, Claude Opus 4.5 is roughly 1.1x cheaper per token on a blended 3:1 input/output basis, which adds up quickly at production volume.

GPT-5.5 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 1.1x cheaper per token

Choose GPT-5.5 if…

  • you want the strongest raw capability — it leads on 5 of 6 shared benchmarks
  • 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

6 benchmarks

Claude Opus 4.5 outperforms in 1 benchmarks (Tau2 Telecom), while GPT-5.5 is better at 5 benchmarks (ARC-AGI v2, GPQA, LiveBench, MCP Atlas, Terminal-Bench 2.0).

GPT-5.5 significantly outperforms across most benchmarks.

Sun Jul 05 2026 • llm-stats.com

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) costs the same as GPT-5.5 ($5.00/1M tokens).

For output processing, Claude Opus 4.5 ($25.00/1M tokens) is 1.2x cheaper than GPT-5.5 ($30.00/1M tokens).

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

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

Lowest available price from all providers
Sun Jul 05 2026 • llm-stats.com
Anthropic
Claude Opus 4.5
Input tokens$5.00
Output tokens$25.00
Best providerAnthropic
OpenAI
GPT-5.5
Input tokens$5.00
Output tokens$30.00
Best providerOpenAI
Notice missing or incorrect data?Start an Issue→

Context Window

Maximum input and output token capacity

GPT-5.5 accepts 1,050,000 input tokens compared to Claude Opus 4.5's 200,000 tokens. GPT-5.5 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
Input1,050,000 tokens
Output128,000 tokens
Sun Jul 05 2026 • llm-stats.com

Input Capabilities

Supported data types and modalities

Both Claude Opus 4.5 and GPT-5.5 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

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

Proprietary

Closed source

Release Timeline

When each model was launched

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

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

Claude Opus 4.5

Nov 24, 2025

7 months ago

GPT-5.5

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 has a cutoff of 2025-12-01.

GPT-5.5 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

Dec 2025

9 mo newer

Provider Availability

Claude Opus 4.5 is available from Anthropic. GPT-5.5 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

openai logo
OpenAI
Input Price:Input: $5.00/1MOutput Price:Output: $30.00/1M
* Prices shown are per million tokens

Outputs Comparison

Notice missing or incorrect data?Start an Issue discussion→

Key Takeaways

Anthropic
Less expensive output tokens
Higher Tau2 Telecom score (98.2% vs 98.0%)
OpenAI
Larger context window (1,050,000 tokens)
Higher ARC-AGI v2 score (85.0% vs 37.6%)
Higher GPQA score (93.6% vs 87.0%)
Higher LiveBench score (80.7% vs 76.0%)
Higher MCP Atlas score (75.3% vs 62.3%)
Higher Terminal-Bench 2.0 score (82.7% vs 59.3%)

Detailed Comparison

Interactive Arena

Judge for yourself.

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

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

FAQ

Common questions about Claude Opus 4.5 vs GPT-5.5.

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

GPT-5.5 significantly outperforms across most benchmarks. Claude Opus 4.5 is made by Anthropic and GPT-5.5 is made by OpenAI. The best choice depends on your use case — compare their benchmark scores, pricing, and capabilities above.

How does Claude Opus 4.5 compare to GPT-5.5 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 scores Tau2 Telecom: 98.0%, ARC-AGI: 95.0%, GPQA: 93.6%, ARC-AGI v2: 85.0%, GDPval-MM: 84.9%.

Is Claude Opus 4.5 cheaper than GPT-5.5?

Both models cost $5.00 per million input tokens.

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

Claude Opus 4.5 supports 200K tokens and GPT-5.5 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?

Key differences include context window (200K vs 1.1M). See the full comparison above for benchmark-by-benchmark results.

Who makes Claude Opus 4.5 and GPT-5.5?

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

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