MODEL COMPARE

GPT-5.1 vs GPT-5.6 Luna Pro: Pricing, Capabilities and Benchmarks

Compare GPT-5.1 and GPT-5.6 Luna Pro across context window, API pricing, modalities, tool use and recommended use cases.

Verified

Model AModel B

DECISION SUMMARY

Decision summary

Recommendations are conditional. Unknown values never count as a loss, and missing comparable benchmarks produce no winner.

Insufficient data

Evidence

comparable_coding_benchmark_missing

No same-source coding benchmark is attached to both model versions.

Insufficient data

Evidence

comparable_agent_benchmark_missing

Capabilities are listed, but a comparable agent benchmark is missing.

GPT-5.6 Luna Pro

Evidence

context_window_larger

GPT-5.1=400000; GPT-5.6 Luna Pro=1050000

GPT-5.6 Luna Pro

Evidence

same_provider_monthly_cost_lower

GPT-5.1=3.25; GPT-5.6 Luna Pro=0.44; input=1000000; cached_input=0; output=200000; provider=OpenRouter

Insufficient data

Evidence

open_weights_support

GPT-5.1=unknown; GPT-5.6 Luna Pro=unknown

MODEL ATTRIBUTES

Source scope: Provider endpoint

Show differences only

Attribute	GPT-5.1	GPT-5.6 Luna Pro	Winner
Context window`context_window_larger`Provider endpoint	400K	1.05M	GPT-5.6 Luna Pro
Maximum output`max_output_larger`Provider endpoint	128K	128K	Tie
Input modalities`input_modalities_differ`Provider endpoint	Image, Text, File	File, Image, Text	Insufficient data
Output modalities`output_modalities_differ`Provider endpoint	Text	Text	Insufficient data
Tool calling`tool_calling_support`Provider endpoint	Supported	Supported	Tie
Structured output`structured_output_support`Provider endpoint	Supported	Supported	Tie
Reasoning`reasoning_support`Model	Supported	Supported	Insufficient data
Open weights`open_weights_support`Model	Unknown	Unknown	Insufficient data
Input price per 1M tokens`input_price_lower`Provider endpoint	$1.25	$0.20	GPT-5.6 Luna Pro
Output price per 1M tokens`output_price_lower`Provider endpoint	$10	$1.2	GPT-5.6 Luna Pro

USAGE ESTIMATOR

Estimate token charges for the selected provider endpoints. Image, audio, request and web-search charges are not included.

This is a provider snapshot, not a quote. Confirm production pricing before use.

Monthly input tokensMonthly output tokensCached input tokens

GPT-5.1$3.25Estimated monthly cost

GPT-5.6 Luna Pro$0.44Estimated monthly cost