Claude Opus 4.5 vs GPT-5.6 Luna
Pricing verdict: Claude Opus 4.5 vs GPT-5.6 Luna: GPT-5.6 Luna is cheaper for input-heavy usage ($1.00/M vs $5.00/M input tokens), while GPT-5.6 Luna is better for long-context tasks (1,050,000 tokens).
Direct answer: choose GPT-5.6 Luna for lower token spend and choose GPT-5.6 Luna when your workload needs longer context.
Compare API pricing, input and output token costs, context windows, and monthly estimates on one page so you can pick the right model fast.
Cost Comparison (1000 input + 500 output tokens, 100 requests/day)
Claude Opus 4.5
GPT-5.6 Luna
Cost Differences
GPT-5.6 Luna costs less than Claude Opus 4.5
Quick Recommendation
Winner for direct API pricing: GPT-5.6 Luna. At the default workload, GPT-5.6 Luna saves about $40.50/month ($492.75/year) versus Claude Opus 4.5.
Feature Comparison
| Feature | Claude Opus 4.5 | GPT-5.6 Luna |
|---|---|---|
| Provider | Anthropic | OpenAI |
| Input Price | $5.00/1M tokens | $1.00/1M tokens |
| Output Price | $25.00/1M tokens | $6.00/1M tokens |
| Context Window | 200,000 tokens | 1,050,000 tokens |
| Max Output | 64,000 tokens | 128,000 tokens |
| Category | flagship | efficient |
| Capabilities | textvisioncodereasoning | textvisioncodereasoning |
| Release Date | 11/1/2025 | 6/26/2026 |
Claude Opus 4.5 vs GPT-5.6 Luna: Which Should You Choose?
Choosing between Claude Opus 4.5 and GPT-5.6 Luna depends on your priorities: cost efficiency, context length, or raw capability. GPT-5.6 Luna is the more affordable option at $1.00/1M input tokens — 80% cheaper than Claude Opus 4.5. Meanwhile, GPT-5.6 Luna offers a significantly larger context window at 1,050,000 tokens vs 200,000 for Claude Opus 4.5.
These models come from different providers — Anthropic and OpenAI — which means different API ecosystems, SDKs, rate limits, and terms of service. If you're already integrated with Anthropic, switching to OpenAIinvolves migration effort beyond just pricing. Factor in your existing infrastructure when deciding.
These models target different tiers: Claude Opus 4.5 is a flagship model while GPT-5.6 Luna is efficient. This means they're optimized for different workloads. Claude Opus 4.5 is built for complex tasks that require deeper reasoning, while GPT-5.6 Luna offers better value for routine operations.
Output costs matter too. Claude Opus 4.5 charges $25.00/1M output tokens vs $6.00 for GPT-5.6 Luna. For generation-heavy workloads (content creation, code generation, summarization), output pricing often dominates your bill. GPT-5.6 Luna has the edge here at $6.00/1M output tokens.
Multimodal capabilities: Both models support vision (image understanding), so you can send images alongside text prompts with either option.
Best Use Cases
Choose Claude Opus 4.5 when:
- • You're already using Anthropic's API ecosystem
Choose GPT-5.6 Luna when:
- • Budget is a primary concern
- • You need a larger context window (1,050,000 tokens)
- • You need longer outputs (up to 128,000 tokens)
- • You're already using OpenAI's API ecosystem
- • You're running high-volume, latency-sensitive workloads
Pros and Caveats at a Glance
Claude Opus 4.5
- • Input pricing: $5.00/M tokens
- • Output pricing: $25.00/M tokens
- • Context window: 200,000 tokens
- • Max output: 64,000 tokens
Watch out for
- • Higher input cost than GPT-5.6 Luna
- • Higher output cost than GPT-5.6 Luna
- • Smaller context window than GPT-5.6 Luna
GPT-5.6 Luna
- • Input pricing: $1.00/M tokens
- • Output pricing: $6.00/M tokens
- • Context window: 1,050,000 tokens
- • Max output: 128,000 tokens
Watch out for
- • Trade-offs are minor in this matchup.
Try Different Scenarios
Use the calculator below to see how costs change with different usage patterns
Claude Opus 4.5 (Anthropic)
GPT-5.6 Luna (OpenAI)
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Sign Up for OpenAI →Frequently Asked Questions
Which is cheaper, Claude Opus 4.5 or GPT-5.6 Luna?▼
What is the context window difference between Claude Opus 4.5 and GPT-5.6 Luna?▼
Which model is better for AI Agent / Agentic Workflows?▼
Which model has better overall pricing for heavy usage?▼
Where can I compare Anthropic and OpenAI API pricing beyond this model matchup?▼
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