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.
Related Glossary Terms
OpenAI's family of generative pre-trained transformer models, the most widely adopted LLMs for commercial AI applications.
ClaudeAnthropic's family of AI models known for long context windows, strong reasoning, and instruction-following capabilities.
Large Language Model (LLM)A neural network trained on massive text datasets that can generate, understand, and reason about human language.
Context WindowThe maximum amount of text (measured in tokens) that an AI model can process in a single request, including both input and output.
Function Calling (Tool Use)An AI capability where the model can decide to invoke external functions or APIs based on the conversation context.
Multimodal AIAI models that can process and generate multiple types of data: text, images, audio, video, and code.
TemperatureA parameter that controls the randomness of AI model outputs, with lower values producing more deterministic responses and higher values producing more creative ones.
Need help choosing?
AI 4U 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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