Claude Opus 5.5 Paid vs 
GPT-6 Luna Paid
Claude Opus 5.5 vs GPT-6 Luna compared — price per token, context window, multimodality, openness and which to choose. Full 2026 breakdown.
Claude Opus 5.5 — full profile › · GPT-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.
$20 /M outputManaged API (no infra to run)
$0.5 /M outputManaged API (no infra to run)
Claude Opus 5.5 vs GPT-6 Luna specs
| Spec | Claude Opus 5.5 | GPT-6 Luna | Winner |
|---|---|---|---|
| Maker | Anthropic | OpenAI | – |
| Type | Proprietary | Proprietary | – |
| Context window | 1M tokens | 1.1M tokens | |
| Input price | $4/M | $0.1/M | |
| Output price | $20/M | $0.5/M | |
| Vision / multimodal | Yes | Yes | = Tie |
| Tool / function calling | Yes | Yes | = Tie |
| Self-hostable | No (API only) | No (API only) | – |
| License | Proprietary | Proprietary | – |
Price gap & when to choose each
GPT-6 Luna is ~40× cheaper than Claude Opus 5.5 on output tokens ($0.5 vs $20 per M tokens).
- You want frontier performance through a managed API
- You value reliability & ecosystem
- You don't want to manage infrastructure
- You want frontier performance through a managed API
- You need the longer 1.1M context window
- You want the lower output price
- You value reliability & ecosystem
- You don't want to manage infrastructure
Feature comparison
| Capability | Claude Opus 5.5 | GPT-6 Luna |
|---|---|---|
| Open weights (downloadable) | ✗ | ✗ |
| Self-hostable | ✗ | ✗ |
| Runs fully offline | ✗ | ✗ |
| Vision / multimodal | ✓ | ✓ |
| Tool / function calling | ✓ | ✓ |
| 1M+ context window | ✓ | ✓ |
Benchmarks: Claude Opus 5.5 vs GPT-6 Luna
Independent benchmark scores measured by Artificial Analysis. Higher is better (except latency).
Benchmark data by Artificial Analysis.
How Claude Opus 5.5 and GPT-6 Luna score
| Criterion | Claude Opus 5.5 | GPT-6 Luna |
|---|---|---|
| Cost-efficiency | 3.0 | 5.0 |
| 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 5.5 Paid
Claude Opus 5.5 is Anthropic's flagship model for demanding reasoning, coding, and long-horizon agentic work, succeeding Claude Opus 5. It is particularly strong at multi-step changes in large codebases, code...
GPT-6 Luna Paid
GPT-6 Luna is the fast, cost-efficient model in OpenAI's GPT-6 series, positioned below GPT-6 Sol. It is suited for high-volume and latency-sensitive workloads such as chat, classification, and lightweight agentic...
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 5.5 vs GPT-6 Luna — which is cheaper?
GPT-6 Luna is cheaper on output ($0.5/M vs $20/M).
Which has the larger context window?
GPT-6 Luna offers the larger context window (1.1M tokens).
Claude Opus 5.5 vs GPT-6 Luna — which should I pick in 2026?
Choose GPT-6 Luna for the lower output price ($0.5/M vs $20/M). It also gives you the larger 1.1M context window.
People also compare
Explore more open-source AI
Browse the full open-source model leaderboard, thousands of tools and live benchmarks — all in one place.
Open the leaderboard →