GPT-5.4 Nano vs GPT-6 Luna: cost per task
GPT-6 Luna is cheaper on 14 of 14 tasks and about 2.4x cheaper on average (geometric mean). GPT-6 Luna has the higher LMArena Text score (1443 vs 1401).
| Task | GPT-5.4 Nano | GPT-6 Luna | Difference |
|---|---|---|---|
| Answer a chat question | 0.15¢ | 0.06¢ | 2.5x |
| Reply to a customer email | 0.02¢ | <0.01¢ | 2.3x |
| Write a 1,500-word blog post | 0.30¢ | 0.12¢ | 2.5x |
| Write 10 product descriptions | 0.13¢ | 0.05¢ | 2.5x |
| Translate 1,000 words | 0.20¢ | 0.08¢ | 2.4x |
| Proofread one page (500 words) | 0.11¢ | 0.04¢ | 2.4x |
| Summarize a 20-page PDF | 0.33¢ | 0.16¢ | 2.1x |
| Extract data from an invoice | 0.08¢ | 0.03¢ | 2.4x |
| Analyze a 200-row spreadsheet | 0.44¢ | 0.19¢ | 2.4x |
| Answer from 5 retrieved documents (RAG) | 0.12¢ | 0.05¢ | 2.2x |
| Classify 100 support tickets | 0.15¢ | 0.06¢ | 2.4x |
| Review 500 lines of code | 0.75¢ | 0.31¢ | 2.4x |
| Write a SQL query | 0.10¢ | 0.04¢ | 2.5x |
| Run a 50-step coding agent | 8.7¢ | 4.1¢ | 2.1x |
Specs and list prices
| GPT-5.4 Nano | GPT-6 Luna | |
|---|---|---|
| Input per 1M | $0.20 | $0.10 |
| Output per 1M | $1.25 | $0.50 |
| Cached input per 1M | $0.02 | $0.01 |
| Context | 400K | 1.05M |
| Providers | 4 | 7 |
| Reasoning | default | default |
| LMArena Text | 1401 | 1443 |
| Released | Mar 17, 2026 | Sep 22, 2026 |
FAQ
Is GPT-5.4 Nano or GPT-6 Luna cheaper?
GPT-6 Luna is cheaper on 14 of 14 tasks and about 2.4x cheaper on average (geometric mean). GPT-6 Luna has the higher LMArena Text score (1443 vs 1401).
How much does GPT-5.4 Nano cost compared to GPT-6 Luna per token?
GPT-5.4 Nano: $0.20 input and $1.25 output per 1M tokens. GPT-6 Luna: $0.10 input and $0.50 output. Token prices alone mislead - models use different numbers of tokens for the same task, which is what the task table shows.