Compare · ModelsLive · 2 picked · head to head
Claude Sonnet 5.5 vs GPT-5.5 Pro
Side by side · benchmarks, pricing, and signals you can act on.
Winner summary
GPT-5.5 Pro wins on 1/1 benchmarks
GPT-5.5 Pro wins 1 of 1 shared benchmarks. Leads in knowledge.
Category leads
knowledge·GPT-5.5 Pro
Hype vs Reality
Attention vs performance
Claude Sonnet 5.5
#11 by perf·#10 by attention
GPT-5.5 Pro
#1 by perf·#4 by attention
Best value
Claude Sonnet 5.5
14.9x better value than GPT-5.5 Pro
Claude Sonnet 5.5
12.5 pts/$
$6.00/M
GPT-5.5 Pro
0.8 pts/$
$105.00/M
Vendor risk
Who is behind the model
Anthropic
$965.0B·Tier 1
OpenAI
$840.0B·Tier 1
Head to head
1 benchmark · 2 models
Claude Sonnet 5.5GPT-5.5 Pro
GPQA diamond
GPT-5.5 Pro leads by +0.1
Graduate-Level Google-Proof QA (Diamond set) · expert-crafted questions in physics, biology, and chemistry that are difficult even for domain PhDs.
Claude Sonnet 5.5
94.1
GPT-5.5 Pro
94.2
Full benchmark table
| Benchmark | Claude Sonnet 5.5 | GPT-5.5 Pro |
|---|---|---|
GPQA diamond Graduate-Level Google-Proof QA (Diamond set) · expert-crafted questions in physics, biology, and chemistry that are difficult even for domain PhDs. | 94.1 | 94.2 |
Pricing · per 1M tokens · projected $/mo at 10M tokens
| Model | Input | Output | Context | Projected $/mo |
|---|---|---|---|---|
| $2.00 | $10.00 | 1.0M tokens (~500 books) | $40.00 | |
| $30.00 | $180.00 | 400K tokens (~200 books) | $675.00 |