GPT 5.4 vs Claude Opus 4.5
GPT 5.4 is 2.0× cheaper on input tokens than Claude Opus 4.5. GPT 5.4 has a longer context window (1M vs 200K). Both models are accessible via the haimaker.ai OpenAI-compatible API at https://api.haimaker.ai/v1.
GPT 5.4
openai/gpt-5.4
Chat
Function CallingVisionReasoning
Claude Opus 4.5
anthropic/claude-opus-4-5-20251101
Chat
Function CallingVisionReasoning
Side-by-side specifications
| Spec | GPT 5.4 | Claude Opus 4.5 |
|---|---|---|
| Provider | OpenAI | Anthropic |
| Full ID | openai/gpt-5.4 | anthropic/claude-opus-4-5-20251101 |
| Mode | chat | chat |
| Parameters | N/A | N/A |
| Context window | 1M | 200K |
| Max output | 128K | 64K |
| Input price (per 1M) | $2.50 | $5.00 |
| Output price (per 1M) | $15.00 | $25.00 |
| License | N/A | N/A |
| Architecture | N/A | N/A |
Feature support
| Feature | GPT 5.4 | Claude Opus 4.5 |
|---|---|---|
| Function Calling | ✓ Supported | ✓ Supported |
| Reasoning | ✓ Supported | ✓ Supported |
| Vision | ✓ Supported | ✓ Supported |
Frequently asked questions
Which is cheaper, GPT 5.4 or Claude Opus 4.5?
GPT 5.4 is cheaper at $2.50 per 1M input tokens vs $5.00 for Claude Opus 4.5.
Which has the larger context window, GPT 5.4 or Claude Opus 4.5?
GPT 5.4 accepts up to 1M input tokens vs 200K for Claude Opus 4.5.
Can I use both GPT 5.4 and Claude Opus 4.5 via the same API?
Yes. haimaker.ai exposes both openai/gpt-5.4 and anthropic/claude-opus-4-5-20251101 on the same OpenAI-compatible endpoint at https://api.haimaker.ai/v1, so you can switch between them by changing the model parameter in your request.
Try GPT 5.4 or Claude Opus 4.5 via the haimaker API
One OpenAI-compatible endpoint. Switch between them by changing the model parameter.