Fast-mode variant of [Opus 5](/anthropic/claude-opus-5) - identical capabilities with higher output speed at 2x pricing relative to regular Opus 5. Learn more in Anthropic's docs: https://platform.claude.com/docs/en/build-with-claude/fast-…
Model details →Claude Opus 5 (Fast) vs OpenAI: GPT-5.4 Image 2
Claude Opus 5 (Fast) and OpenAI: GPT-5.4 Image 2 are evenly matched on 6 axes — pick the one whose provider, latency, or licensing fits your stack.
[GPT-5.4](https://openrouter.ai/openai/gpt-5.4) Image 2 combines OpenAI's GPT-5.4 model with state-of-the-art image generation capabilities from GPT Image 2. It enables rich multimodal workflows, allowing users to seamlessly move between re…
Model details →Side-by-side comparison
| Capability | Claude Opus 5 (Fast) | OpenAI: GPT-5.4 Image 2 | Winner |
|---|---|---|---|
| Context window Maximum number of input tokens the model can attend to in a single request. | 1M | 272K | 🏆 Claude Opus 5 (Fast) |
| Input price (per 1M) Cost per million input tokens billed by the provider. | $10.00 | $8.00 | 🏆 OpenAI: GPT-5.4 Image 2 |
| Output price (per 1M) Cost per million output tokens billed by the provider. | $50.00 | $15.00 | 🏆 OpenAI: GPT-5.4 Image 2 |
| Tool / function calling First-class support for emitting structured tool calls. | Yes | — | 🏆 Claude Opus 5 (Fast) |
| Vision input Accepts image inputs alongside text. | Yes | Yes | Tie |
| Reasoning mode Internal chain-of-thought / extended-thinking support. | Yes | Yes | Tie |
Frequently asked questions
Is Claude Opus 5 (Fast) better than OpenAI: GPT-5.4 Image 2?
Claude Opus 5 (Fast) and OpenAI: GPT-5.4 Image 2 are evenly matched on 6 axes — pick the one whose provider, latency, or licensing fits your stack.
What's the price difference between Claude Opus 5 (Fast) and OpenAI: GPT-5.4 Image 2?
Input: $10.00 vs $8.00 per 1M tokens. Output: $50.00 vs $15.00 per 1M tokens.
What context windows do Claude Opus 5 (Fast) and OpenAI: GPT-5.4 Image 2 support?
Claude Opus 5 (Fast) supports up to 1M tokens. OpenAI: GPT-5.4 Image 2 supports up to 272K tokens.
Do both Claude Opus 5 (Fast) and OpenAI: GPT-5.4 Image 2 support tool calling?
Claude Opus 5 (Fast): yes. OpenAI: GPT-5.4 Image 2: not advertised.
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