Fast-mode variant of [Opus 4.8](/anthropic/claude-opus-4.8) - identical capabilities with higher output speed at 2x pricing relative to regular Opus 4.8. Learn more in Anthropic's docs: https://platform.claude.com/docs/en/build-with-claude…
Model details →Anthropic: Claude Opus 4.8 (Fast) vs OpenAI: GPT-5.4 Pro
Anthropic: Claude Opus 4.8 (Fast) wins on 2 of 6 axes — pricing and capability skew in its favour for most workloads.
GPT-5.4 Pro is OpenAI's most advanced model, building on GPT-5.4's unified architecture with enhanced reasoning capabilities for complex, high-stakes tasks. It features a 1M+ token context window (922K input, 128K...
Model details →Side-by-side comparison
| Capability | Anthropic: Claude Opus 4.8 (Fast) | OpenAI: GPT-5.4 Pro | Winner |
|---|---|---|---|
| Context window Maximum number of input tokens the model can attend to in a single request. | 1M | 1.1M | 🏆 OpenAI: GPT-5.4 Pro |
| Input price (per 1M) Cost per million input tokens billed by the provider. | $10.00 | $30.00 | 🏆 Anthropic: Claude Opus 4.8 (Fast) |
| Output price (per 1M) Cost per million output tokens billed by the provider. | $50.00 | $180.00 | 🏆 Anthropic: Claude Opus 4.8 (Fast) |
| Tool / function calling First-class support for emitting structured tool calls. | Yes | Yes | Tie |
| 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 Anthropic: Claude Opus 4.8 (Fast) better than OpenAI: GPT-5.4 Pro?
Anthropic: Claude Opus 4.8 (Fast) wins on 2 of 6 axes — pricing and capability skew in its favour for most workloads.
What's the price difference between Anthropic: Claude Opus 4.8 (Fast) and OpenAI: GPT-5.4 Pro?
Input: $10.00 vs $30.00 per 1M tokens. Output: $50.00 vs $180.00 per 1M tokens.
What context windows do Anthropic: Claude Opus 4.8 (Fast) and OpenAI: GPT-5.4 Pro support?
Anthropic: Claude Opus 4.8 (Fast) supports up to 1M tokens. OpenAI: GPT-5.4 Pro supports up to 1.1M tokens.
Do both Anthropic: Claude Opus 4.8 (Fast) and OpenAI: GPT-5.4 Pro support tool calling?
Anthropic: Claude Opus 4.8 (Fast): yes. OpenAI: GPT-5.4 Pro: yes.
Compare Anthropic: Claude Opus 4.8 (Fast) with other models
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