GPT-6 Luna vs Grok 4.6
Grok 4.6 was superseded by Grok 4.7. The grades below are the last ones measured, so read them as history rather than as this week's board. See the current roster.
Grok 4.6 leads overall, C- to D. By suite, GPT-6 Luna takes real-world issues (C- to D) and Grok 4.6 takes spec planning (C to D+). Take GPT-6 Luna anyway when you want the side that is 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: Grok 4.6 vs GPT-6 Luna
Grok 4.6 leads overall, C- to D. By suite: GPT-6 Luna takes real-world issues, C- to D (57% vs 47% capability); Grok 4.6 takes spec planning, C to D+ (66% vs 55% capability); Grok 4.6 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). Grok 4.6 used 13% of SuperGrok Plus's weekly limit per pass, $0.157 per task at the listed price. GPT-6 Luna is faster on real-world issues: a median task takes 1m 4s against 7m 10s. Both finished every task on it. Reasons to pick GPT-6 Luna anyway: it is faster on real-world issues (1m 4s vs 7m 10s median) and it leads on real-world issues (C- to D).
Changed since the previous graded week: GPT-6 Luna: real-world issues D+ to C-, spec planning C- to D+; Grok 4.6: real-world issues C- to D, real-world issues usage 4% to 3% of the weekly limit, vibe coding C+ to C-.
| Dimension | GPT-6 Luna | Grok 4.6 | Advantage |
|---|---|---|---|
| Capability | 57% | 47% | +10% (GPT-6 Luna leads) |
| Median task time | 1m 4s | 7m 10s | 6m 6s faster (GPT-6 Luna leads) |
| Approx. task cost | not measured | $0.046 / 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. Grok 4.6: 3.0% of SuperGrok 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 | GPT-6 Luna | Grok 4.6 | Advantage |
|---|---|---|---|
| Capability | 55% | 66% | +11% (Grok 4.6 leads) |
| Median task time | 1m 20s | 45m 26s | 44m 6s faster (GPT-6 Luna leads) |
| Approx. task cost | <$0.011 / task | $0.575 / task | $0.563 / 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. Grok 4.6: 10.0% of SuperGrok Plus (10.0% / 1w) per run. Each figure is a share of that agent's own plan, so there is no delta to draw.
| Dimension | GPT-6 Luna | Grok 4.6 | Advantage |
|---|---|---|---|
| Capability | 31% | 61% | +30% (Grok 4.6 leads) |
| Median task time | 1m 24s | 11m 14s | 9m 50s faster (GPT-6 Luna leads) |
| Approx. task cost | <$0.046 / task | <$0.230 / task | $0.184 / task lower (GPT-6 Luna 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. Grok 4.6: under 1% of SuperGrok Plus 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-6 Luna or Grok 4.6?
Grok 4.6 clears higher: tier 4 of 5 versus tier 2 for GPT-6 Luna 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 Grok 4.6?
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). Grok 4.6 used 13% of SuperGrok Plus's weekly limit per pass, $0.157 per task at the listed price.
What do GPT-6 Luna and Grok 4.6 cost a month?
GPT-6 Luna runs on ChatGPT Plus at $20/month (public price as of 2026-07-20). Grok 4.6 runs on SuperGrok Plus at $100/month (public price as of 2026-09-14).