Claude Opus 5 vs GPT-5.5 Pro
Claude Opus 5 and GPT-5.5 Pro are closely matched at 54.9 and 45.0 on the LLM Stats Score. Claude Opus 5 is 6.8x cheaper per token.
Anthropic · OpenAI · Updated for 2026
Which is better?
Claude Opus 5 and GPT-5.5 Pro are closely matched on the overall LLM Stats Score at 54.9 and 45.0.
In the 2 individual benchmarks reported for both models, Claude Opus 5 wins 2; this is a narrower head-to-head signal than the composite indexes.
On price, Claude Opus 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.
Based on current LLM Stats indexes, shared benchmarks, pricing, and model metadata for 2026.
Choose Claude Opus 5
- you value its reported benchmark strengths — it wins 2 of 2 exact shared results
- cost matters — it's about 6.8x cheaper per token
- you want the most recent training data — it shipped Jul 2026
Choose GPT-5.5 Pro
- you process long inputs — it offers a 1,050,000 token context window
At a glance
The differences that matter most.
Individual benchmarks
13 reported for Claude Opus 5 · 5 for GPT-5.5 Pro
Claude Opus 5 outperforms in 2 benchmarks (BrowseComp, Humanity's Last Exam), while GPT-5.5 Pro is better at 0 benchmarks.
Claude Opus 5 significantly outperforms across most benchmarks.
Human preference
Blind head-to-head votes and playground preference scores
Pricing Analysis
Price comparison per million tokens
For input processing, Claude Opus 5 ($5.00/1M tokens) is 6.0x cheaper than GPT-5.5 Pro ($30.00/1M tokens).
For output processing, Claude Opus 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 5.*
* Using a 3:1 ratio of input to output tokens
Context Window
Maximum input and output token capacity
GPT-5.5 Pro 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
Documented input modalities across available providers
Both Claude Opus 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 5
GPT-5.5 Pro
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 Pro was released on 2026-04-23.
Claude Opus 5 is 3 months newer than GPT-5.5 Pro.
Jul 24, 2026
1 months ago
3mo newerApr 23, 2026
4 months ago
Knowledge Cutoff
When training data ends
GPT-5.5 Pro 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 Pro'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, DeepInfra. GPT-5.5 Pro is available from OpenAI.
Claude Opus 5
GPT-5.5 Pro
Outputs Comparison
Judge for yourself.
Run your own prompts against Claude Opus 5 and GPT-5.5 Pro side-by-side, then vote on the output you prefer.
FAQ
Common questions about Claude Opus 5 vs GPT-5.5 Pro.