claude-sonnet-5 vs gpt-5.6-luna
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 | claude-sonnet-5 | gpt-5.6-luna | Advantage |
|---|---|---|---|
| Capability | 53% | 51% | +3% (claude-sonnet-5 leads) |
| Median task time | 5m 6s | 2m 15s | 2m 51s faster (gpt-5.6-luna leads) |
| Approx. task cost | $0.009 / task | $0.009 / task | $0.000 / task lower (claude-sonnet-5 leads) |
claude-sonnet-5: about 9.7% of Claude Max 20x (about 9.7% / 5h, 1.0% / 1w) per run (estimated: 2 of 15 cells measured no share of their own). gpt-5.6-luna: 3.0% of ChatGPT Plus (3.0% / 1w) per run. Each figure is a share of that agent's own plan, so there is no delta to draw.
| Dimension | claude-sonnet-5 | gpt-5.6-luna | Advantage |
|---|---|---|---|
| Capability | 37% | 56% | +19% (gpt-5.6-luna leads) |
| Median task time | 5m 21s | 2m 59s | 2m 23s faster (gpt-5.6-luna leads) |
| Approx. task cost | $0.005 / task | $0.012 / task | $0.007 / task lower (claude-sonnet-5 leads) |
claude-sonnet-5: 0.4% of Claude Max 20x (0.4% / 5h, 0.2% / 1w) per good solve. gpt-5.6-luna: 0.3% of ChatGPT Plus (0.3% / 1w) 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, claude-sonnet-5 or gpt-5.6-luna?
claude-sonnet-5 clears higher: tier 3 of 5 versus tier 0 for gpt-5.6-luna on real-world@v3, our private suite of real-world coding problems. Latest measurement 2026-08-11.
How much do claude-sonnet-5 and gpt-5.6-luna cost?
claude-sonnet-5 runs on Claude Max 20x at $200/month (public price as of 2026-08-05). gpt-5.6-luna runs on ChatGPT Plus at $20/month (public price as of 2026-07-20).