For a standard chatbot, GPT-5.4 saves about 8% — roughly $97/month at this volume. Not a huge difference. The choice here comes down to quality and ecosystem: Claude's conversational style vs GPT's tool use, or your existing Anthropic vs OpenAI infrastructure.
Use Case 2: Code Review & Refactoring
Typical request: ~3,000 input tokens (file + context), ~800 output tokens. At 1,000 requests/day:
For code review, the cost gap is modest. But Sonnet 5's 1M context means you can feed it an entire repo for cross-file analysis — something GPT-5.4 can't do as easily at 400K. If your workflow involves understanding large codebases holistically, Sonnet 5's context advantage is worth more than the 7% price difference.
Use Case 3: Document Analysis (Long Context)
Typical request: ~50,000 input tokens (long document), ~2,000 output tokens. At 200 requests/day:
Here's where it gets interesting. GPT-5.4 is 14% cheaper for document analysis — but Sonnet 5 can handle documents up to 1M tokens that GPT-5.4 physically can't process in a single request. For truly long documents (legal contracts, research papers, codebases), Sonnet 5 is the only option in this price tier.
Quality & Capabilities
Both models are strong all-rounders, but they have different strengths:
- Claude Sonnet 5 — Excels at nuanced writing, careful reasoning, following complex instructions, and maintaining consistency across long outputs. Anthropic's safety training also makes it more reliable for sensitive applications.
- GPT-5.4 — Strong tool use, function calling, and structured output. OpenAI's ecosystem (Assistants API, fine-tuning, GPT Store integration) gives it an edge if you're already in the OpenAI stack.
Migration Cost: Switching Between Them
If you're currently on one and considering the other, the API migration is straightforward:
- From GPT-5.4 to Sonnet 5: Change the model ID to
claude-sonnet-5-20260701. Same message format, similar API structure. Anthropic's API is compatible with most OpenAI SDK wrappers. - From Sonnet 5 to GPT-5.4: Change the model ID to
gpt-5.4. Function calling syntax is nearly identical.
Both support streaming, function calling, vision, and system prompts. The migration effort is minimal — usually under an hour for a typical integration.
See the full 67-model comparison — including budget and premium tiers
Compare All Models →The Verdict
| Input price | GPT-5.4 wins ($2.50 vs $3.00) |
| Output price | Tie ($15.00 each) |
| Context window | Sonnet 5 wins (1M vs 400K) |
| Coding | Sonnet 5 slight edge |
| Tool use | GPT-5.4 slight edge |
| Best for high-volume | GPT-5.4 (17% cheaper input) |
Choose Claude Sonnet 5 if you need long context (1M tokens), work with large codebases, or value Anthropic's safety and instruction-following quality.
Choose GPT-5.4 if you're optimizing for cost at scale, need strong tool use/function calling, or are already in the OpenAI ecosystem.
For most production workloads, the cost difference is under 10% — so pick based on quality and context needs, not price.
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