Is GPT-5.6 Luna or Claude Opus 5.5 cheaper?

GPT-5.6 Luna is cheaper for a typical request of 1,000 input and 500 output tokens: $0.0008 versus $0.014 for Claude Opus 5.5, about 94% less.

What are the per-token prices of GPT-5.6 Luna and Claude Opus 5.5?

GPT-5.6 Luna costs $0.20 input and $1.20 output per million tokens. Claude Opus 5.5 costs $4.00 input and $20.00 output per million tokens.

Which has the larger context window, GPT-5.6 Luna or Claude Opus 5.5?

GPT-5.6 Luna has the larger context window: 1.05M tokens versus 1M for Claude Opus 5.5.

OpenAI vs Anthropic

GPT-5.6 Luna vs Claude Opus 5.5: pricing comparison

GPT-5.6 Luna costs 17.5× less than Claude Opus 5.5 for a typical 1,000-input, 500-output request. Here is how the two compare on price, context and discounts.

Prices last updated: September 25, 2026

	GPT-5.6 Luna	Claude Opus 5.5
Provider	OpenAI	Anthropic
Input per 1M tokens	$0.20	$4.00
Output per 1M tokens	$1.20	$20.00
Context window	1.05M	1M
Batch discount	50% off	50% off
Typical request (1,000 in / 500 out)	$0.0008	$0.014
Monthly at 1,000 requests/day	$24.00	$420.00

GPT-5.6 Luna: Inputs above 272K tokens are billed at a higher long-context rate ($0.40 / $1.80).

Claude Opus 5.5: Successor to Claude Opus 5 at a lower per-token price.

Compare with your own numbers

Input tokens

Output tokens

Requests / day

GPT-5.6 Luna per request: $0.0008
Per month: $24.00

Claude Opus 5.5 per request: $0.014
Per month: $420.00

Cost by task

Cost per 1,000 requests at standard prices.
Task	Tokens (in / out)	GPT-5.6 Luna	Claude Opus 5.5
Short chat reply	500 / 300	$0.46	$8.00
RAG answer	6,000 / 600	$1.92	$36.00
Summarize a long document	12,000 / 1,000	$3.60	$68.00
Output-heavy generation	1,000 / 4,000	$5.00	$84.00

Output tokens usually dominate the bill — see input vs output token cost.

Frequently asked questions

Is GPT-5.6 Luna or Claude Opus 5.5 cheaper?: GPT-5.6 Luna is cheaper for a typical request of 1,000 input and 500 output tokens: $0.0008 versus $0.014 for Claude Opus 5.5, about 94% less.
What are the per-token prices of GPT-5.6 Luna and Claude Opus 5.5?: GPT-5.6 Luna costs $0.20 input and $1.20 output per million tokens. Claude Opus 5.5 costs $4.00 input and $20.00 output per million tokens.
Which has the larger context window, GPT-5.6 Luna or Claude Opus 5.5?: GPT-5.6 Luna has the larger context window: 1.05M tokens versus 1M for Claude Opus 5.5.

More comparisons

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