GPT-6 Luna vs GPT-6 Sol
GPT-6 Sol was superseded by GPT-6.1 Sol. The grades below are the last ones measured, so read them as history rather than as this week's board. See the current roster.
GPT-6 Sol leads overall, C- to D. By suite, real-world issues is even at C- and GPT-6 Sol takes spec planning (C- to D+). Take GPT-6 Luna anyway when you want the side that is faster on real-world issues. Both agents run the same private suite cut headless through their own tools, each on its own subscription.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, C- to D. By suite: real-world issues is even at C- (57% vs 55% capability); GPT-6 Sol takes spec planning, C- to D+ (60% vs 55% capability); GPT-6 Sol takes vibe coding, C- to F (61% vs 31% capability). GPT-6 Luna used <1% of ChatGPT Plus's weekly limit per pass; at the ~$100 tier the board defaults to that is an estimated ~<0.2% of ChatGPT Pro 5x's weekly limit (est). GPT-6 Sol used 7% of ChatGPT Plus's weekly limit per pass, $0.017 per task at the listed price; at the ~$100 tier the board defaults to that is an estimated ~1.4% of ChatGPT Pro 5x's weekly limit (est, about $0.017 per task). GPT-6 Luna is faster on real-world issues: a median task takes 1m 4s against 1m 41s. Both finished every task on it. Reasons to pick GPT-6 Luna anyway: it is faster on real-world issues (1m 4s vs 1m 41s median).
Changed since W39: GPT-6 Luna: real-world issues D+ to C-, spec planning C- to D+; GPT-6 Sol: real-world issues D- to C-, real-world issues usage 4% to 5% of the weekly limit, spec planning C to C-, spec planning usage 1% to 2% of the weekly limit, vibe coding D+ to C-.
| Dimension | GPT-6 Luna | GPT-6 Sol | Advantage |
|---|---|---|---|
| Capability | 57% | 55% | +2% (GPT-6 Luna leads) |
| Median task time | 1m 4s | 1m 41s | 37s faster (GPT-6 Luna leads) |
| Approx. task cost | not measured | $0.015 / task | - |
GPT-6 Luna: under 1% of ChatGPT Plus (2.0% / 5h) per run. Its weekly limit holds about 6 of the week's 33.6 5h windows. GPT-6 Sol: 5.0% of ChatGPT Plus (35.0% / 5h, 5.0% / 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 | 55% | 60% | +6% (GPT-6 Sol leads) |
| Median task time | 1m 20s | 2m 58s | 1m 38s faster (GPT-6 Luna leads) |
| Approx. task cost | <$0.011 / task | $0.023 / task | $0.011 / task lower (GPT-6 Luna leads) |
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: 2.0% of ChatGPT Plus (10.0% / 5h, 2.0% / 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 | 31% | 61% | +30% (GPT-6 Sol leads) |
| Median task time | 1m 24s | 2m 44s | 1m 20s faster (GPT-6 Luna leads) |
| Approx. task cost | <$0.046 / task | $0.018 / task | $0.028 / task lower (GPT-6 Sol leads) |
GPT-6 Luna: under 1% of ChatGPT Plus 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 (1.8% / 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 2026-09-27.
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; at the ~$100 tier the board defaults to that is an estimated ~<0.2% of ChatGPT Pro 5x's weekly limit (est). GPT-6 Sol used 7% of ChatGPT Plus's weekly limit per pass, $0.017 per task at the listed price; at the ~$100 tier the board defaults to that is an estimated ~1.4% of ChatGPT Pro 5x's weekly limit (est, about $0.017 per task).
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).