GPT-6 Luna vs GPT-6 Sol
GPT-6 Sol leads overall, D+ to D. GPT-6 Luna is about 5.0x cheaper per task. By suite, GPT-6 Luna takes real-world issues (D+ to D-) and GPT-6 Sol takes spec planning (C to C-). Take GPT-6 Luna anyway when you want the side that is cheaper per task, faster on real-world issues and ahead on real-world issues.Measured
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.
Verdict: GPT-6 Sol vs GPT-6 Luna
GPT-6 Sol leads overall, D+ to D. By suite: GPT-6 Luna takes real-world issues, D+ to D- (50% vs 38% capability); GPT-6 Sol takes spec planning, C to C- (64% vs 61% capability); GPT-6 Sol takes vibe coding, D+ to F (51% vs 33% capability). GPT-6 Luna used 1% of ChatGPT Plus's weekly limit per pass, $0.002 per task at the listed price; at the ~$100 tier the board defaults to that is an estimated ~0.2% of ChatGPT Pro 5x's weekly limit (est, about $0.002 per task). GPT-6 Sol used 5% of ChatGPT Plus's weekly limit per pass, $0.012 per task at the listed price; at the ~$100 tier the board defaults to that is an estimated ~1% of ChatGPT Pro 5x's weekly limit (est, about $0.012 per task). Per task, GPT-6 Luna is about 5.0x cheaper ($0.002 vs $0.012). GPT-6 Luna is faster on real-world issues: a median task takes 1m 0s against 2m 44s. Both finished every task on it. Reasons to pick GPT-6 Luna anyway: it is cheaper per task ($0.002 vs $0.012), it is faster on real-world issues (1m 0s vs 2m 44s median) and it leads on real-world issues (D+ to D-).
| Dimension | GPT-6 Luna | GPT-6 Sol | Advantage |
|---|---|---|---|
| Capability | 50% | 38% | +12% (GPT-6 Luna leads) |
| Median task time | 1m 0s | 2m 44s | 1m 44s faster (GPT-6 Luna leads) |
| Approx. task cost | $0.003 / task | $0.012 / task | $0.009 / task lower (GPT-6 Luna leads) |
GPT-6 Luna: 1.0% of ChatGPT Plus (1.0% / 5h, 1.0% / 1w) per run. Its weekly limit holds about 6 of the week's 33.6 5h windows. GPT-6 Sol: 4.0% of ChatGPT Plus (37.0% / 5h, 4.0% / 1w) per run. Its weekly limit holds about 6 of the week's 33.6 5h windows. Each figure is a share of that agent's own plan, so there is no delta to draw.
| Dimension | GPT-6 Luna | GPT-6 Sol | Advantage |
|---|---|---|---|
| Capability | 61% | 64% | +3% (GPT-6 Sol leads) |
| Median task time | 1m 8s | 2m 23s | 1m 15s faster (GPT-6 Luna leads) |
| Approx. task cost | <$0.011 / task | $0.011 / task | Even |
GPT-6 Luna: under 1% of ChatGPT Plus per run. Its weekly limit holds about 6 of the week's 33.6 5h windows. GPT-6 Sol: 1.0% of ChatGPT Plus (8.0% / 5h, 1.0% / 1w) per run. Its weekly limit holds about 6 of the week's 33.6 5h windows. Each figure is a share of that agent's own plan, so there is no delta to draw.
| Dimension | GPT-6 Luna | GPT-6 Sol | Advantage |
|---|---|---|---|
| Capability | 33% | 51% | +18% (GPT-6 Sol leads) |
| Median task time | 1m 37s | 3m 4s | 1m 28s faster (GPT-6 Luna leads) |
| Approx. task cost | not measured | $0.018 / task | - |
GPT-6 Luna: under 1% of ChatGPT Plus (0.4% / 5h) per good solve. Its weekly limit holds about 6 of the week's 33.6 5h windows. GPT-6 Sol: 0.4% of ChatGPT Plus (2.4% / 5h, 0.4% / 1w) per good solve. Its weekly limit holds about 6 of the week's 33.6 5h windows. 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-6 Luna or GPT-6 Sol?
GPT-6 Luna clears higher: tier 2 of 5 versus tier 1 for GPT-6 Sol on real-world@v3, our private suite of real-world coding problems. Latest measurement 2026-09-23.
Which is cheaper per task, GPT-6 Luna or GPT-6 Sol?
GPT-6 Luna used 1% of ChatGPT Plus's weekly limit per pass, $0.002 per task at the listed price; at the ~$100 tier the board defaults to that is an estimated ~0.2% of ChatGPT Pro 5x's weekly limit (est, about $0.002 per task). GPT-6 Sol used 5% of ChatGPT Plus's weekly limit per pass, $0.012 per task at the listed price; at the ~$100 tier the board defaults to that is an estimated ~1% of ChatGPT Pro 5x's weekly limit (est, about $0.012 per task). Per task, GPT-6 Luna is about 5.0x cheaper ($0.002 vs $0.012).
What do GPT-6 Luna and GPT-6 Sol cost a month?
GPT-6 Luna runs on ChatGPT Plus at $20/month (public price as of 2026-07-20). GPT-6 Sol runs on ChatGPT Plus at $20/month (public price as of 2026-07-20).