Claude Opus 5 (Fast) Paid vs 
GPT-5.6 Luna Paid
Claude Opus 5 (Fast) vs GPT-5.6 Luna compared — price per token, context window, multimodality, openness and which to choose. Full 2026 breakdown.
Claude Opus 5 (Fast) — full profile › · GPT-5.6 Luna — full profile ›
Prices & specs refreshed from live data · olud.ai
Open-model prices = cheapest provider via OpenRouter; official maker rates may be higher.
Claude Opus 5 (Fast) vs GPT-5.6 Luna specs
| Spec | Claude Opus 5 (Fast) | GPT-5.6 Luna |
|---|---|---|
| Maker | Anthropic | OpenAI |
| Type | Proprietary | Proprietary |
| Context window | 1M tokens | 1.1M tokens |
| Input price | $10/M | $0.5/M |
| Output price | $50/M | $3/M |
| Vision / multimodal | Yes | Yes |
| Tool / function calling | Yes | Yes |
| Self-hostable | No (API only) | No (API only) |
| License | Proprietary | Proprietary |
Feature comparison
| Capability | Claude Opus 5 (Fast) | GPT-5.6 Luna |
|---|---|---|
| Open weights (downloadable) | ✗ | ✗ |
| Self-hostable | ✗ | ✗ |
| Runs fully offline | ✗ | ✗ |
| Vision / multimodal | ✓ | ✓ |
| Tool / function calling | ✓ | ✓ |
| 1M+ context window | ✓ | ✓ |
Benchmarks: Claude Opus 5 (Fast) vs GPT-5.6 Luna
Independent benchmark scores measured by Artificial Analysis. Higher is better (except latency).
Benchmark data by Artificial Analysis.
How Claude Opus 5 (Fast) and GPT-5.6 Luna score
| Criterion | Claude Opus 5 (Fast) | GPT-5.6 Luna |
|---|---|---|
| Cost-efficiency | 2.0 | 4.0 |
| Context window | 5.0 | 5.0 |
| Openness | 1.5 | 1.5 |
| Self-hosting | 1.0 | 1.0 |
| Multimodality | 5.0 | 5.0 |
Scores come from live data — output price (cost), context length, open vs closed weights (openness & self-hosting) and vision/tool support (multimodality). Raw task quality isn't scored here; it depends on your benchmark — see the verdict.
What each model is
Claude Opus 5 (Fast) Paid
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-
GPT-5.6 Luna Paid
GPT-5.6 Luna is a fast, cost-efficient model in OpenAI's GPT-5.6 series. It is suited for high-volume, latency-sensitive tasks such as chat, classification, and lightweight agentic workflows, providing capable reasoning for...
Other models in these families
These variants are tracked but not compared here — one page per family keeps the comparison readable.
Frequently asked questions
Claude Opus 5 (Fast) vs GPT-5.6 Luna — which is cheaper?
GPT-5.6 Luna is cheaper on output ($3/M vs $50/M).
Which has the larger context window?
GPT-5.6 Luna offers the larger context window (1.1M tokens).
Claude Opus 5 (Fast) vs GPT-5.6 Luna — which should I pick in 2026?
Choose GPT-5.6 Luna for the lower output price ($3/M vs $50/M). It also gives you the larger 1.1M context window.
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