Model Comparison
Claude Opus 5 vs GPT-5.5Which is better in 2026?
Claude Opus 5 significantly outperforms across most benchmarks. Claude Opus 5 is 1.1x cheaper per token.
Verdict: Claude Opus 5 vs GPT-5.5 — which is better?
Claude Opus 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 5 outperforms in 6 benchmarks (BrowseComp, DeepSWE 1.1, FrontierCode 1.1, GDPval-AA, Humanity's Last Exam, Legal Agent Benchmark), while GPT-5.5 is better at 0 benchmarks. Claude Opus 5 significantly outperforms across most benchmarks.
On price, Claude Opus 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 5 if…
- you want the strongest raw capability — it leads on 6 of 6 shared benchmarks
- cost matters — it's about 1.1x cheaper per token
- you want the most recent training data — it shipped Jul 2026
Choose GPT-5.5 if…
- you process long inputs — it offers a 1,050,000 token context window
Performance Benchmarks
Comparative analysis across standard metrics
Claude Opus 5 outperforms in 6 benchmarks (BrowseComp, DeepSWE 1.1, FrontierCode 1.1, GDPval-AA, Humanity's Last Exam, Legal Agent Benchmark), while GPT-5.5 is better at 0 benchmarks.
Claude Opus 5 significantly outperforms across most benchmarks.
Arena Performance
Human preference votes
Pricing Analysis
Price comparison per million tokens
For input processing, Claude Opus 5 ($5.00/1M tokens) costs the same as GPT-5.5 ($5.00/1M tokens).
For output processing, Claude Opus 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 5.*
* Using a 3:1 ratio of input to output tokens
Context Window
Maximum input and output token capacity
GPT-5.5 accepts 1,050,000 input tokens compared to Claude Opus 5's 1,000,000 tokens. Both models can generate responses up to 128,000 tokens.
Input Capabilities
Supported data types and modalities
Both Claude Opus 5 and GPT-5.5 support multimodal inputs.
They are both capable of processing various types of data, offering versatility in application.
Claude Opus 5
GPT-5.5
License
Usage and distribution terms
Both models are licensed under proprietary licenses.
Both models have usage restrictions defined by their respective organizations.
Proprietary
Closed source
Proprietary
Closed source
Release Timeline
When each model was launched
Claude Opus 5 was released on 2026-07-24, while GPT-5.5 was released on 2026-04-23.
Claude Opus 5 is 3 months newer than GPT-5.5.
Jul 24, 2026
0 days ago
3mo newerApr 23, 2026
3 months ago
Knowledge Cutoff
When training data ends
GPT-5.5 has a documented knowledge cutoff of 2025-12-01, while Claude Opus 5's cutoff date is not specified.
We can confirm GPT-5.5's training data extends to 2025-12-01, but cannot make a direct comparison without Claude Opus 5's cutoff date.
—
Dec 2025
Provider Availability
Claude Opus 5 is available from Anthropic. GPT-5.5 is available from OpenAI.
Claude Opus 5
GPT-5.5
Outputs Comparison
Key Takeaways
Claude Opus 5
View detailsAnthropic
GPT-5.5
View detailsOpenAI
Detailed Comparison
Interactive Arena
Judge for yourself.
Run your own prompts against Claude Opus 5 and GPT-5.5 side-by-side, then vote on the output you prefer.
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FAQ
Common questions about Claude Opus 5 vs GPT-5.5.