GPT-6 Luna vs Grok 4.5
Grok 4.5 was superseded by Grok 4.6. 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 4.5 leads overall, C- to D. GPT-6 Luna is about 13x cheaper per task. By suite, Grok 4.5 takes real-world issues (C- to D+) and vibe coding (C- to F). Take GPT-6 Luna anyway when you want the side that is cheaper per task and faster 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 4.5 vs GPT-6 Luna
Grok 4.5 leads overall, C- to D. By suite: Grok 4.5 takes real-world issues, C- to D+ (60% vs 50% capability); Grok 4.5 takes vibe coding, C- to F (59% vs 33% capability). Only GPT-6 Luna has run spec planning. 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). Grok 4.5 used 6.9% of SuperGrok's weekly limit per pass, $0.032 per task at the listed price. Per task, GPT-6 Luna is about 13x cheaper ($0.002 vs $0.032). GPT-6 Luna is faster on real-world issues: a median task takes 1m 0s against 3m 9s. Both finished every task on it. Reasons to pick GPT-6 Luna anyway: it is cheaper per task ($0.002 vs $0.032) and it is faster on real-world issues (1m 0s vs 3m 9s median).
Changed since W32: Grok 4.5: real-world issues usage 8.0% to 6.9% of the weekly limit.
| Dimension | GPT-6 Luna | Grok 4.5 | Advantage |
|---|---|---|---|
| Capability | 50% | 60% | +10% (Grok 4.5 leads) |
| Median task time | 1m 0s | 3m 9s | 2m 9s faster (GPT-6 Luna leads) |
| Approx. task cost | $0.003 / task | $0.032 / task | $0.029 / 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. Grok 4.5: 6.9% of SuperGrok (6.9% / 1w) per run. Each figure is a share of that agent's own plan, so there is no delta to draw.
Only GPT-6 Luna has run this suite, so there is no head-to-head yet.
| Dimension | GPT-6 Luna | Grok 4.5 | Advantage |
|---|---|---|---|
| Capability | 33% | 59% | +26% (Grok 4.5 leads) |
| Median task time | 1m 37s | 3m 40s | 2m 3s faster (GPT-6 Luna leads) |
| Approx. task cost | not measured | $0.031 / 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. Grok 4.5: 0.4% of SuperGrok (0.4% / 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, GPT-6 Luna or Grok 4.5?
Grok 4.5 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 2026-09-23.
Which is cheaper per task, GPT-6 Luna or Grok 4.5?
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). Grok 4.5 used 6.9% of SuperGrok's weekly limit per pass, $0.032 per task at the listed price. Per task, GPT-6 Luna is about 13x cheaper ($0.002 vs $0.032).
What do GPT-6 Luna and Grok 4.5 cost a month?
GPT-6 Luna runs on ChatGPT Plus at $20/month (public price as of 2026-07-20). Grok 4.5 runs on SuperGrok at $30/month (public price as of 2026-07-20).