ChatGPT vs Claude: API Cost & Quality Comparison (2025)
Compare GPT-4o and Claude Sonnet 4 on API pricing, context window, speed, and real-world performance. Which AI API is right for your use case?
Full Feature Comparison
| Feature | GPT-4o | Claude Sonnet 4 |
|---|---|---|
| Input price (per 1M tokens) | $2.50 | $3.00 |
| Output price (per 1M tokens) | $10.00 | $15.00 |
| Context window | 128K tokens | 200K tokens |
| Vision / image input | Yes | Yes |
| Prompt caching discount | 50% off | 90% off |
| Function calling | Yes | Yes |
| Batch API discount | 50% off | 50% off |
| Response speed (avg) | ~50 tok/s | ~60 tok/s |
| Rate limits (tier 1)Claude limits are stricter for new accounts | 500 RPM | 50 RPM |
| JSON mode / structured output | Yes | Yes (tool use) |
| Free tier | ChatGPT web app only | Claude.ai web app only |
| Enterprise compliance | SOC 2, HIPAA add-on | SOC 2, HIPAA available |
Cost Comparison Calculator
Running GPT-4o vs Claude Sonnet 4 at the same usage parameters.
Claude Sonnet 4 saves $0.00/month (0% cheaper)
Deep Dive Analysis
Cost: GPT-4o wins on price
GPT-4o is cheaper per token — $2.50 input vs $3.00 for Claude Sonnet 4. But Claude's prompt caching is dramatically more aggressive (90% vs 50% discount), making it competitive or cheaper for applications with repeated system prompts or large static context.
Long documents: Claude wins
Claude Sonnet 4's 200K context window (vs GPT-4o's 128K) handles longer documents without chunking. For legal document analysis, book-length codebases, or multi-hour transcript processing, Claude's larger window reduces architectural complexity significantly.
Coding: Claude has the edge
On SWE-bench and HumanEval benchmarks, Claude Sonnet 4 consistently outperforms GPT-4o on complex multi-file coding tasks. GPT-4o is competitive on single-function completion. For agentic coding workflows (Cursor, Windsurf), Claude is the more common choice.
Ecosystem: GPT-4o wins
OpenAI has the larger developer ecosystem — more third-party integrations, more tutorials, and the dominant consumer mindshare. If you need integrations with LangChain, LlamaIndex, or most SaaS platforms, GPT-4o is better supported out of the box.
Frequently Asked Questions
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