OpenAI

GPT-6 Luna API pricing.

GPT-6 Luna is OpenAI’s model on the API market, released 22 Sept 2026. Prices are per million tokens in USD, as last read from the price list.

$0.10Input / 1M
$0.50Output / 1M
1.1MContext
128KMax output
Capability scores
Epoch AI
Maths3 of 4 benchmarks78
Science and knowledge2 of 2 benchmarks64
Coding1 of 2 benchmarks27
Reasoning and puzzles2 of 2 benchmarks16
Agents and long tasks2 of 3 benchmarks10

Each bar is this model's score in that area. The white tick marks the best score any model Epoch has tested reaches there.

Epoch Capabilities Index
157
Range 154 to 159 · #28 of 271 models Epoch has scored
Maths
78average of 3 of 4 Epoch results
FrontierMath (tiers 1 to 3) (max)79%
FrontierMath (tier 4) (max)56%
OTIS Mock AIME (max)99%
Science and knowledge
64average of 2 of 2 Epoch results
GPQA Diamond (max)90%
SimpleQA Verified (max)41%
Coding
27average of 1 of 2 Epoch results
MirrorCode (max)27%
Reasoning and puzzles
16average of 2 of 2 Epoch results
Chess puzzles (max)36%
Mystery game puzzles (max)7.0%
Agents and long tasks
10average of 2 of 3 Epoch results
Furniture assembly (max)44%
SpireClimb (game agent) (max)0.0%

The index combines many benchmarks into one general-capability score; the range is how sure Epoch is of the number. Each area score is this site's average of the model's Epoch results in that area, where 0 is what guessing would score and 100 is perfect. Compare every model, and value for money →

Source: Epoch AI, Capabilities & benchmarking (licensed CC BY 4.0). Data refreshed 2 November 2026. These are Epoch's own tests; other benchmark sites can rank models differently.

Cheaper models that come close
Our working on Epoch's index
  1. GLM-5.3-Flash · Z.ai (Zhipu AI)index 153.22 (4 below) · 78% cheaper
  2. DeepSeek V4 Flash 0731 · DeepSeekindex 154.94 (2 below) · 26% cheaper
  3. DeepSeek V4.1 Flash · DeepSeekindex 156.11 (1 below) · 21% cheaper

Models within 5 points of GPT-6 Luna on Epoch's Capabilities Index that cost less, comparing a typical chat mix (three parts input to one part output). A few points of index is a small difference and says nothing about your task: a place to start testing, not a verdict. Capability against price for every model.

Specification
USD per million tokens
Provider
OpenAI
Model id
openai/gpt-6-luna
Input
$0.10
Output
$0.50
Cached input
$0.010
Context window
1.1M tokens
Maximum output
128K tokens
Takes
file, image, text
Returns
text
Tool use
Yes
Reasoning
Yes
Released
22 Sept 2026
First tracked
22 Sept 2026

At $0.10 per million input tokens, GPT-6 Luna is dearer than 54 of the 340 models on the price list.

Price changes
Tracked since 17 Sept 2026

No price change has been recorded since tracking began on 17 Sept 2026. Prices are checked every six hours, and any change is listed here and on model changes.

Want an email when this model's price changes? Tell us →

Coverage
5 stories
  1. The Decoder ·
    Inception's Mercury 3 diffusion model claims to beat GPT-6 Luna and Claude Haiku 5.5 at a fraction of the wait
  2. SiliconANGLE AI ·
    Inception says Mercury 3 beats GPT-6 Luna and Claude Haiku 5.5 at up to 8x the speed
  3. Latent Space ·
    [AINews] Claude Haiku 5.5 — better than GPT-6 Luna at the same pricing
  4. Simon Willison's Weblog ·
    Claude Opus 5.5, GPT-6 Sol, GPT-6 Luna, and a new price war
  5. AWS Machine Learning Blog ·
    Bring more intelligence to everyday work with GPT-6 Sol and GPT-6 Luna on Amazon Bedrock
Other entries for this model
More from OpenAI
Cheapest input first
  1. gpt-oss-20b$0.030 in · $0.13 out
  2. GPT-5 Nano$0.050 in · $0.40 out
  3. gpt-oss-safeguard-20b$0.075 in · $0.30 out
  4. GPT-6 Luna Pro$0.10 in · $0.50 out
  5. GPT-4.1 Nano$0.10 in · $0.40 out
  6. gpt-oss-120b$0.15 in · $0.60 out
  7. GPT-4o-mini$0.15 in · $0.60 out
  8. GPT-4o-mini (2024-07-18)$0.15 in · $0.60 out

Prices and specifications come from OpenRouter’s catalogue, last read 2 Nov 2026. A provider’s own price may differ; how this is collected.