GPT-5.6 Luna (low reasoning effort)
Data: JevBench v1.6.1, published 2026-10-06
Capability 94.5 · API offering, ranked on the API leaderboard · outside the Jev-class caps (cost 6.6× Jev (v1.5 reference); latency 2.6× Jev (v1.5 reference)), below the Capability ranking
Measured 2026-10-06 on A4 ∪ P, 600 items, equated (+2.57 I / +3.35 C); round score-a4-2.
proprietary API
intelligence
94.1
calibration
94.9
speed
73.1
cost
30.2
Composite (secondary)
21.4 · Composite rank #17 of 27 on the API leaderboard
Cost and measurement conditions
$0.213 per 1,000 decisions (public tariff)
measured: token usage of the 6 Oct 2026 A4 u P run x tariff USD 0.2/M input, 1.2/M output (spec gpt-5.6-luna.json), per 1,000 decisions on the v1.6.1 common cost basis (591 of 600 items; the 9 A4 u P items outside the Jev reference's accepted input range are excluded, cost-basis-a4.json)
p50 latency: 1.6 s
none (API)
Breakdowns (not part of the score)
Chance-corrected competence (0 = chance, 100 = perfect) on A4 ∪ P (600 items: 300 open + 300 sealed; fewer sealed items than the full set, so wider uncertainty). Raw values, not equated. Category cells use A4+P+L1+L2+L3; per-type/tier cells use the original basis above. Radars against Jev.
| Request type | Open | Sealed |
|---|---|---|
| choice | 93.9 | 90.3 |
| noul | 100.0 | 94.6 |
| score | 79.3 | 90.8 |
Capability by subject topic
| Rules, policy & law | 90.5 | n=1133 |
|---|---|---|
| Coding & software | 83.4 | n=202 |
| Math & numbers | 87.1 | n=269 |
| Finance & commerce | 93.6 | n=178 |
| Support & operations | 95.4 | n=109 |
| Everyday language | 91.9 | n=130 |
| Safety & security | 97.4 | n=84 |
Use cases (TypeSafe categories)
| Model routing | 87.4 | n=267 |
|---|---|---|
| Legal & compliance | 92.9 | n=269 |
| Customer support | 91.0 | n=156 |
| E-commerce | 97.1 | n=88 |
| Insurance claims | 95.4 | n=92 |
| Risk assessment | 84.1 | n=88 |
| Financial crime | 94.6 | n=76 |
| Feature extraction | 82.3 | n=90 |
| Lead generation | 94.6 | n=86 |
| Recruiting | 84.4 | n=88 |
| Knowledge graphs | 74.0 | n=82 |
| LLM guardrails | 92.2 | n=82 |
| Moderation | 93.7 | n=69 |
| Code linting | 88.4 | n=81 |
| Search & retrieval | 96.6 | n=84 |
| Science | 92.1 | n=82 |
| Advertising | 89.7 | n=85 |
| Gaming | 85.4 | n=79 |
| Demand forecasting | 94.4 | n=72 |
Cells need at least 15 answered items; † fewer than 30 (indicative only, listed below the radar in the compare view).
Previous measurement (v1.5.x, not comparable)
Capability 94.5 · composite 22.4 · cost $0.205 per 1,000 decisions (not published)
Last measured 2026-09-28, measurement release v1.5.0. Older method and scale; the current figures above replace it.