ModelPickr

Compare / GPT

GPT · canonical pair

GPT-5.4 vs GPT-5.6 Luna

Alphabetical by model id, so this URL is the one to index. GPT-5.4 is openai/gpt-5.4. GPT-5.6 Luna is openai/gpt-5.6-luna. Both are among the models the most providers list, inside the GPT group.

A

GPT-5.4

$37.50

per month at the reference workload

  • Reasoning
  • Tool use
  • Structured output
  • Vision
  • Long context

vs

B

GPT-5.6 Luna

$3.00

per month at the reference workload

  • Reasoning
  • Tool use
  • Structured output
  • Vision
  • Long context
100 requests a day, 2,000 input tokens and 500 output tokens, no cache hits. A light chat workload so the rate cards are comparable.
SpecGPT-5.4GPT-5.6 Luna
Monthly, reference workload$37.50$3.00
Input / 1M$2.50$0.20
Output / 1M$15.00$1.20
Cache read / 1M$0.25$0.02
Cache write / 1M—$0.25
Context1,050,0001,050,000
Max output128,000128,000
ReasoningYesYes
Tool callsYesYes
VisionYesYes
Open weightsNoNo
Providers3944
Released2026-03-052026-07-09

Same workload, your numbers

Prices are USD per 1M tokens. A month is 30 days. Cache hits use the cache-read rate when the model has one; otherwise the cache field is ignored.

Estimated monthly cost

GPT-5.4

$37.50

GPT-5.4 costs $34.50 more per month than GPT-5.6 Luna at these inputs.

monthly = requests/day × 30 × (input tokens × (1 − cache hit) × input price + input tokens × cache hit × cache-read price + output tokens × output price) ÷ 1,000,000