Claude Haiku 5.5 vs GPT-6 Luna
A side-by-side look at Claude Haiku 5.5 from Anthropic and GPT-6 Luna from OpenAI: list prices, context windows, licensing and capabilities, with monthly costs worked out for three common workloads.
The short version
- Price: effectively tied on blended list price.
- Larger context window: GPT-6 Luna (1.05M vs 1M tokens).
- Inputs: Claude Haiku 5.5 accepts text, images, pdf; GPT-6 Luna accepts text, images.
- Newer release: Claude Haiku 5.5 (October 7, 2026).
Specs side by side
| Claude Haiku 5.5 | GPT-6 Luna | |
|---|---|---|
| Provider | Anthropic | OpenAI |
| Released | Oct 7, 2026 | Sep 22, 2026 |
| Status | Current | Current |
| Weights and license | Closed Proprietary | Closed Proprietary |
| Tier | Efficient | Efficient |
| Context window | 1M | 1.05M |
| Max output | 125K | 125K |
| Input per 1M tokens | $0.10 | $0.10 |
| Output per 1M tokens | $0.50 | $0.50 |
| Cached input per 1M | $0.01 | $0.01 |
| Input types | Text, Images, PDF | Text, Images |
| Reasoning mode | Yes | Yes |
| Tool calling | Yes | Yes |
| Parameters | Undisclosed | Undisclosed |
Highlighted cells are better on that line: lower price or larger limit. List prices, standard tier, checked October 10, 2026.
What they cost for real workloads
| Workload (monthly) | Claude Haiku 5.5 | GPT-6 Luna | Difference |
|---|---|---|---|
| Support chatbot30,000 conversations a month, 2,000 input and 400 output tokens each | $12 | $12 | |
| Document summaries2,000 documents a month, 12,000 input and 800 output tokens each | $3.20 | $3.20 | |
| Coding agent1,000 tasks a month, 60,000 input and 6,000 output tokens each | $9.00 | $9.00 |
Standard rates without caching or batch discounts. Try your own volumes.
Choose Claude Haiku 5.5 if
- you mainly need it for agents, which Anthropic emphasizes for this model
- your inputs include pdf
- $0.10 input and $0.50 output per million tokens for prompts up to 100K tokens
- 1M-token context window and 128K-token output limit
Choose GPT-6 Luna if
- you need more than 1M tokens of context in one request
- $0.10 input and $0.50 output per million tokens
- reasoning can be set to none for quick, low-cost calls
Our take
Both are positioned for customer support, data extraction, high volume. On list price the gap is about 1.0×, which matters most for high-volume, input-heavy workloads. Quality differences shift with every release, so treat this page as a shortlist tool: run 20-50 of your real tasks through both, score the outputs, and divide the bill by the number of tasks each one got right.
Read the full profiles: Claude Haiku 5.5 and GPT-6 Luna. For help designing that test, see how to read LLM benchmarks.
Frequently asked questions
Which is cheaper, Claude Haiku 5.5 or GPT-6 Luna?
GPT-6 Luna has the lower list price: $0.10 input and $0.50 output per million tokens, versus $0.10 and $0.50. Discounts for caching and batch processing can change the real bill, so price your own token mix.
Which has the bigger context window?
GPT-6 Luna accepts 1.05M tokens, compared with 1M for Claude Haiku 5.5.
Can I run Claude Haiku 5.5 or GPT-6 Luna on my own hardware?
Claude Haiku 5.5 is closed, so only through hosted APIs. GPT-6 Luna is closed, so only through hosted APIs.
Is Claude Haiku 5.5 better than GPT-6 Luna?
It depends on the task. Public benchmarks and arena rankings move with every release and rarely match a specific workload. Use the specs here to shortlist, then test both on your own prompts and compare accuracy, latency and cost per correct answer.
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