GPT-5.6 Luna vs GPT-5.6 Terra: API Pricing & Benchmarks
GPT-5.6 Luna vs GPT-5.6 Terra — or, searched the other way round, GPT-5.6 Terra vs GPT-5.6 Luna: official API prices, what the same workload costs on each, and every published benchmark score, side by side. Every figure comes straight from the data below; this page does not pick a winner.
Price per 1M tokens
| GPT-5.6 Luna | GPT-5.6 Terra | |
|---|---|---|
| Input | $0.20 | $2.00 |
| Output | $1.20 | $12.00 |
| Blended | $0.45 | $4.50 |
| Developer | OpenAI | OpenAI |
| Released | 2026-07-09 | 2026-07-09 |
GPT-5.6 Luna: Higher rates apply above a context threshold; see the official site
GPT-5.6 Terra: Higher rates apply above a context threshold; see the official site
Prices: official list prices as recorded by models.dev (GPT-5.6 Luna) and models.dev (GPT-5.6 Terra).
Cost of the same workload
| Workload | Tokens | GPT-5.6 Luna | GPT-5.6 Terra | Difference |
|---|---|---|---|---|
| Short chat reply | 500 in / 300 out | 0.046¢ | 0.46¢ | GPT-5.6 Luna cheaper by 0.414¢ |
| RAG query | 4,000 in / 500 out | 0.14¢ | $0.0140 | GPT-5.6 Luna cheaper by $0.0126 |
| Long document summary | 50,000 in / 1,000 out | $0.0112 | $0.1120 | GPT-5.6 Luna cheaper by $0.1008 |
| Code review of a 2k-line file | 30,000 in / 2,000 out | 0.84¢ | $0.0840 | GPT-5.6 Luna cheaper by $0.0756 |
| 1,000 chat replies/day for 30 days | 30,000 × (500 in / 300 out) | $13.80 | $138.00 | GPT-5.6 Luna cheaper by $124.20 |
Cost = (input tokens ÷ 1,000,000 × input price) + (output tokens ÷ 1,000,000 × output price), using each model's own prices above.
Benchmarks
| Benchmark | GPT-5.6 Luna | GPT-5.6 Terra |
|---|---|---|
| Epoch Capabilities Index (ECI) | 156.8 epoch · as of 2026-07-09 |
160.9 epoch · as of 2026-07-09 |
| Epoch Mock AIME accuracy | 98.3% epoch · as of 2026-07-09 |
99.7% epoch · as of 2026-07-09 |
| Epoch FrontierMath (T1–3) accuracy | 82.1% epoch · as of 2026-07-09 |
86.0% epoch · as of 2026-07-09 |
| Arena text rating | 1453 arena · as of 2026-10-28 |
1467 arena · as of 2026-10-28 |
| Arena coding rating (human preference votes, not task accuracy) | 1502 arena · as of 2026-10-28 |
1517 arena · as of 2026-10-28 |
| Arena math rating | 1477 arena · as of 2026-10-28 |
1480 arena · as of 2026-10-28 |
Full pages
GPT-5.6 Luna pricing GPT-5.6 Terra pricing GPT-5.6 Luna token counter GPT-5.6 Terra token counter
FAQ
Which is cheaper, GPT-5.6 Luna or GPT-5.6 Terra?
GPT-5.6 Luna is cheaper on blended price: $0.45 vs $4.50 per 1M tokens, which is $4.05 less per 1M tokens (90.0% below GPT-5.6 Terra).
How do the input and output prices of GPT-5.6 Luna and GPT-5.6 Terra compare?
GPT-5.6 Luna costs $0.20 per 1M input tokens and $1.20 per 1M output tokens. GPT-5.6 Terra costs $2.00 per 1M input tokens and $12.00 per 1M output tokens.
What are the ECI scores of GPT-5.6 Luna and GPT-5.6 Terra?
GPT-5.6 Luna scores 156.8 on the Epoch Capabilities Index (ECI); GPT-5.6 Terra scores 160.9 on the Epoch Capabilities Index (ECI).
Where does the GPT-5.6 Luna vs GPT-5.6 Terra comparison data come from?
Prices come from models.dev and LiteLLM (open MIT-licensed catalogs); benchmark scores come from Epoch AI and LMArena (open CC BY 4.0 datasets). This page states the numbers side by side and does not pick an overall winner — see /data-sources/.