Claude Sonnet 4.5 vs GPT-5 Pro
A side-by-side comparison of two multimodal models — real specs, pricing, strengths and weaknesses, and a clear verdict on which to choose. Kept current by our agents.
Quick verdict: which should you choose?
Choose Claude Sonnet 4.5 if you need
- ✓Handles very large inputs across image, text, and file modalities in a single workflow
- ✓Strong integration of text, image, and file data for document-heavy tasks
- ✓Flexible reasoning over extended 400k context without native real-time access
- ✓Proprietary OpenAI model suited to complex multimodal file analysis
Choose GPT-5 Pro if you need
- ✓Reliable handling of the largest 1M context windows with careful reasoning
- ✓Strong safety alignment and effective multimodal file support at lower cost
- ✓Detailed analysis that avoids overly specialized topic variability
- ✓Anthropic proprietary model when refusals and verbosity are acceptable trade-offs
Verdict
Claude Sonnet 4.5 leads on cost and maximum context length while GPT-5 Pro leads on explicit multimodal integration for document-heavy tasks. GPT-5 Pro's $120/1M price and 400k context contrast with Claude's $15/1M and 1M context. Neither model discloses intelligence or speed metrics, so selection depends on whether users prioritize integration depth or scale plus safety alignment.
Claude Sonnet 4.5 vs GPT-5 Pro: side by side
| Spec | Claude Sonnet 4.5 | GPT-5 Pro | Winner |
|---|---|---|---|
| Intelligence | — | — | Tie |
| Output speed | — | — | Tie |
| Output price | $15.00/1M | $120.00/1M | Claude Sonnet 4.5 |
| Context | 1000K | 400K | Claude Sonnet 4.5 |
| Params | — | — | Tie |
| Provider | Anthropic | OpenAI | Tie |
Detailed analysis
Pricing
Winner: Claude Sonnet 4.5GPT-5 Pro lists output at $120 per million tokens. Claude Sonnet 4.5 lists output at $15 per million tokens. The sixfold price difference favors Claude for high-volume multimodal workloads.
Context Length
Winner: Claude Sonnet 4.5GPT-5 Pro supports 400000 tokens. Claude Sonnet 4.5 supports 1000000 tokens. Claude therefore accommodates twice the context for large-scale multimodal reasoning.
Multimodal Integration
Winner: GPT-5 ProGPT-5 Pro strengths explicitly include strong integration of text, image, and file data plus suitability for document-heavy workflows. Claude strengths emphasize effective multimodal file support alongside safety alignment. GPT-5 Pro therefore shows more targeted multimodal workflow claims.
Safety and Reasoning Style
Winner: Claude Sonnet 4.5Claude lists strong safety alignment and careful detailed reasoning as core strengths. GPT-5 Pro lists no safety claims and notes performance variability on specialized topics. Users needing cautious outputs therefore align with Claude.
Claude Sonnet 4.5
Pros
- +Strong safety alignment
- +Reliable handling of large contexts
- +Careful and detailed reasoning
Cons
- –Can be overly cautious with refusals
- –Vision performance varies by image complexity
- –May produce verbose responses
GPT-5 Pro
Pros
- +Handles very large inputs across modalities
- +Strong integration of text, image, and file data
- +Suitable for document-heavy workflows
Cons
- –No native real-time information access
- –Performance can vary on highly specialized topics
- –Higher computational cost with maximum context
Summary: Claude Sonnet 4.5 vs GPT-5 Pro
Select GPT-5 Pro when maximum multimodal integration across documents is required despite higher cost. Select Claude Sonnet 4.5 when larger context, lower price, and safety alignment matter most. Direct head-to-head intelligence or speed data is unavailable in the given facts.
Frequently asked questions
Neither is universally better; GPT-5 Pro leads on multimodal integration while Claude Sonnet 4.5 leads on context size and price.