GPT-5.2 vs Claude Opus 4.6
A detailed comparison of OpenAI GPT-5.2 and Anthropic Claude Opus 4.6 covering context windows, reasoning, pricing, and real-world performance for production AI applications.
Specs Comparison
| Feature | GPT-5.2 (OpenAI) | Claude Opus 4.6 (Anthropic) |
|---|---|---|
| Provider | OpenAI | Anthropic |
| Context Window | 128K tokens | 1M tokens |
| Max Output | 16K tokens | 32K tokens |
| Multimodal | Text, Images, Audio | Text, Images |
| Reasoning Modes | none / medium / high | Adaptive thinking (low / medium / high) |
| API Style | Conversations + Responses API | Messages API |
| Input Pricing | $2.00 / 1M tokens | $15.00 / 1M tokens |
| Output Pricing | $8.00 / 1M tokens | $75.00 / 1M tokens |
| Function Calling | Yes | Yes (Tool Use) |
| Web Search | Built-in (Responses API) | No (requires external integration) |
| Speed (TTFT) | ~500ms | ~800ms |
| Knowledge Cutoff | Oct 2025 | Jan 2026 |
GPT-5.2 (OpenAI)
Pros
- Built-in web search via Responses API
- Conversations API keeps context automatically
- Strongest function-calling reliability
- Mature ecosystem with extensive documentation
- Lower latency for short tasks
- Broad multimodal support including audio
Cons
- Smaller context window (128K vs 1M)
- Higher cost for long-context tasks
- No adaptive thinking — fixed reasoning modes
- Temperature not supported on gpt-5-mini
Best for
Chat applications, function calling, web search, and tasks needing a mature API ecosystem with built-in persistence.
Claude Opus 4.6 (Anthropic)
Pros
- Massive 1M token context window
- Adaptive thinking adjusts reasoning depth automatically
- Superior long-document analysis and codebase understanding
- More recent knowledge cutoff
- Longer max output (32K tokens)
- Strong instruction following and safety alignment
Cons
- Significantly higher pricing
- No built-in web search
- No audio input support
- Higher latency on complex reasoning tasks
Best for
Large codebase analysis, long document processing, complex reasoning tasks, and applications requiring massive context windows.
Verdict
Choose GPT-5.2 for chat apps, web search features, and cost-sensitive applications with shorter contexts. Choose Claude Opus 4.6 when you need to process huge documents, analyze entire codebases, or require the deepest reasoning capabilities. For most production apps, GPT-5.2 offers the best value; for specialized AI-heavy products, Opus 4.6 is unmatched.
Frequently Asked Questions
Which is better, GPT-5.2 or Claude Opus 4.6?
It depends on your use case. GPT-5.2 excels at chat applications, web search, and function calling with a mature API ecosystem. Claude Opus 4.6 is superior for long-document analysis, codebase understanding, and complex reasoning with its 1M token context window.
Is GPT-5.2 cheaper than Claude Opus 4.6?
Yes, significantly. GPT-5.2 costs $2/$8 per million input/output tokens, while Claude Opus 4.6 costs $15/$75. For high-volume applications, GPT-5.2 can be 7-9x cheaper.
Which AI model has a larger context window?
Claude Opus 4.6 has a 1M token context window (roughly 2,500 pages), compared to GPT-5.2 with 128K tokens (roughly 300 pages). Opus 4.6 is the clear choice for processing very long documents or entire codebases.
Can GPT-5.2 and Claude Opus 4.6 both do function calling?
Yes, both support function calling (called "Tool Use" in Anthropic terminology). GPT-5.2 is generally considered more reliable for complex multi-step function calling chains, while Claude Opus 4.6 has strong instruction following for tool use.
Need help choosing?
AI 4U Labs builds with both GPT-5.2 and Claude Opus 4.6. We'll recommend the right tool for your specific use case and build it for you in 2-4 weeks.
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