gpt-5.6-luna vs composer-2.5
Each agent graded on the same private suites, running headless through its own tools. Advantages are oriented so a win is a win, whichever way the metric runs.
| Dimension | gpt-5.6-luna | composer-2.5 | Advantage |
|---|---|---|---|
| Capability | 53% | 57% | +3% (composer-2.5 leads) |
| Median task time | 1m 59s | 1m 30s | 28s faster (composer-2.5 leads) |
| Approx. task cost | $0.009 / task | $0.023 / task | $0.015 / task lower (gpt-5.6-luna leads) |
gpt-5.6-luna: 2.9% of ChatGPT Plus (2.9% / 1w) per run. composer-2.5: 1.8% of Cursor Pro (1.8% / 1m) per run. Each figure is a share of that agent's own plan, so there is no delta to draw.
| Dimension | gpt-5.6-luna | composer-2.5 | Advantage |
|---|---|---|---|
| Capability | 58% | 51% | +7% (gpt-5.6-luna leads) |
| Median task time | 2m 11s | 4m 30s | 2m 19s faster (gpt-5.6-luna leads) |
| Approx. task cost | $0.004 / task | $0.029 / task | $0.025 / task lower (gpt-5.6-luna leads) |
gpt-5.6-luna: 0.3% of ChatGPT Plus (0.3% / 1w) per run. composer-2.5: 0.6% of Cursor Pro (0.6% / 1m) per run. Each figure is a share of that agent's own plan, so there is no delta to draw.
| Dimension | gpt-5.6-luna | composer-2.5 | Advantage |
|---|---|---|---|
| Capability | 28% | 37% | +9% (composer-2.5 leads) |
| Median task time | 2m 44s | 1m 51s | 53s faster (composer-2.5 leads) |
| Approx. task cost | $0.008 / task | $0.024 / task | $0.017 / task lower (gpt-5.6-luna leads) |
gpt-5.6-luna: 0.2% of ChatGPT Plus (0.2% / 1w) per good solve. composer-2.5: 0.1% of Cursor Pro (0.1% / 1m) per good solve. Each figure is a share of that agent's own plan, so there is no delta to draw.
Grades and deltas are comparable only within a suite version. See methodology.
Frequently asked questions
Which is better for coding, gpt-5.6-luna or composer-2.5?
gpt-5.6-luna clears higher: tier 3 of 5 versus tier 2 for composer-2.5 on real-world@v3, our private suite of real-world coding problems. Latest measurement 2026-08-17.
How much do gpt-5.6-luna and composer-2.5 cost?
gpt-5.6-luna runs on ChatGPT Plus at $20/month (public price as of 2026-07-20). composer-2.5 runs on Cursor Pro at $20/month (public price as of 2026-07-20).