AI model comparison
Claude Haiku 5.5 vs GPT-6 Luna Pro
Pricing, context window, benchmarks, and features compared side by side. Or skip the guesswork and send one prompt to both.
Anthropic
Claude Haiku 5.5
Claude Haiku 5.5 is Anthropic's small, fast model for high-volume, cost-sensitive work such as summarization, subagents, and browser use.
- Input / 1M
- $0.10
- Output / 1M
- $0.50
- Context
- 1M
OpenAI
GPT-6 Luna Pro
GPT-6 Luna Pro is the same underlying model as [GPT-6 Luna](https://openrouter.ai/openai/gpt-6-luna), served with `reasoning.mode` set to `pro` for higher-quality responses on complex tasks.
- Input / 1M
- $0.10
- Output / 1M
- $0.50
- Context
- 1.05M
At a glance
Quick verdict
How the two models stack up on the things people ask about most.
Lower price
Tie
Same price for a typical chat
Higher intelligence score
Tie
Not enough benchmark data
Larger context window
GPT-6 Luna Pro
1.05M vs 1M tokens
Newer release
Claude Haiku 5.5
Released October 7, 2026
Benchmarks
Benchmark scores
Independent scores from Artificial Analysis. Higher is better.
Intelligence index
Claude Haiku 5.543.4GPT-6 Luna ProNot availableCoding index
Claude Haiku 5.5Not availableGPT-6 Luna ProNot availableAgentic index
Claude Haiku 5.5Not availableGPT-6 Luna ProNot availablePricing
Claude Haiku 5.5 vs GPT-6 Luna Pro API pricing
Per-token API rates. Cheaper option highlighted.
| Metric | Claude Haiku 5.5 | GPT-6 Luna Pro |
|---|---|---|
| Input tokensPer 1M tokens | $0.10 | $0.10 |
| Output tokensPer 1M tokens | $0.50 | $0.50 |
| Cached input (read)Per 1M tokens | $0.01 | $0.01 |
| Cache writePer 1M tokens | $0.13 | $0.13 |
| Long-context pricingPer 1M tokens, for very long prompts | $0.50 in / $2.50 out above 100K | $0.20 in / $0.75 out above 272K |
| Web searchPer request | $0.01 | $0.01 |
What it costs in practice
Estimated cost per 1,000 requests at standard rates. Coding and long-document figures also show the cost when the input is already cached.
Chat message
2K in, 500 out
Claude Haiku 5.5$0.45GPT-6 Luna Pro$0.45Coding task
30K in, 4K out
Claude Haiku 5.5$5$2.30 cachedGPT-6 Luna Pro$5$2.30 cachedLong document summary
150K in, 2K out
Claude Haiku 5.5$16$2.50 cachedGPT-6 Luna Pro$16$2.50 cachedSpecs
Context window and capabilities
How much each model can read, how much it can write, and what it accepts as input.
| Metric | Claude Haiku 5.5 | GPT-6 Luna Pro |
|---|---|---|
| Context window | 1M tokens | 1.05M tokens |
| Max output | 128K tokens | 128K tokens |
| Input types | File, Image, Text | File, Image, Text |
| Output types | Text | Text |
| Reasoning effort levels | Max, Extra high, High, Medium, Low | Max, Extra high, High, Medium, Low, None |
| Default reasoning effort | Medium | Medium |
| Release date | October 7, 2026 | September 22, 2026 |
Features
Supported features
API features available for each model.
| Metric | Claude Haiku 5.5 | GPT-6 Luna Pro |
|---|---|---|
| Tool calling | Supported | Supported |
| Structured outputs | Supported | Supported |
| JSON mode | Supported | Supported |
| Reasoning | Supported | Supported |
| Temperature | Not supported | Not supported |
| Stop sequences | Supported | Not supported |
| Deterministic seed | Not supported | Supported |
| Verbosity control | Supported | Supported |
Keep exploring
More on these models
Other head-to-heads, the full model page, and the alternatives list for each model.
Claude Haiku 5.5View full model details- Claude Haiku 5.5 vs MiMo-V2.6-Pro
- Claude Haiku 5.5 vs GLM 5.3
- Claude Haiku 5.5 vs Kimi K3
- Claude Haiku 5.5 vs GLM 5.3 Flash
- Claude Haiku 5.5 vs Gemini 3.8 Flash
- Claude Haiku 5.5 vs DeepSeek V4.1 Flash
- Claude Haiku 5.5 vs MiMo-V2.6-Flash
- Claude Haiku 5.5 vs GPT-6 Luna
- Claude Haiku 5.5 vs DeepSeek V4 Flash 0731
- Claude Haiku 5.5 vs GPT-5.6 Luna
Our take
GPT-6 Luna Pro has the larger context window (1.05M vs 1M tokens). The right pick depends on your workload, so the quickest way to settle it is to send the same prompt to both and compare.
FAQ
Frequently asked questions
Is Claude Haiku 5.5 or GPT-6 Luna Pro cheaper?
Claude Haiku 5.5 and GPT-6 Luna Pro cost the same for a typical chat (2K input tokens and 500 output tokens). Claude Haiku 5.5 costs $0.10 per 1M input tokens and $0.50 per 1M output tokens, and GPT-6 Luna Pro costs $0.10 per 1M input tokens and $0.50 per 1M output tokens.
Which has a bigger context window, Claude Haiku 5.5 or GPT-6 Luna Pro?
GPT-6 Luna Pro supports up to 1.05M tokens of context, compared with 1M for Claude Haiku 5.5.
Can I use Claude Haiku 5.5 and GPT-6 Luna Pro at the same time?
Yes. Shortcut Chat sends one prompt to multiple models at once, so you can see Claude Haiku 5.5 and GPT-6 Luna Pro answer side by side and keep the better response.
Why choose? Ask both.
Send one prompt to Claude Haiku 5.5 and GPT-6 Luna Pro at the same time. Compare the answers side by side and keep the best one.