GPT-6 Astra vs Grok 4.5
Grok 4.5 was superseded by Grok 4.7.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.
GPT-6 Astra leads overall, C to C-. Grok 4.5 is about 1.7x cheaper per task. By suite, Grok 4.5 takes real-world issues (C- to D) and GPT-6 Astra takes vibe coding (C+ to C-). Take Grok 4.5 anyway when you want the side that is cheaper per task 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 4.5 vs GPT-6 Astra
GPT-6 Astra leads overall, C to C-. By suite: Grok 4.5 takes real-world issues, C- to D (60% vs 43% capability); GPT-6 Astra takes vibe coding, C+ to C- (74% vs 59% capability). Only GPT-6 Astra has run spec planning. GPT-6 Astra used 22% of ChatGPT Plus's weekly limit per pass, $0.053 per task at the listed price; at the ~$100 tier the board defaults to that is an estimated ~4.4% of ChatGPT Pro 5x's weekly limit (est, about $0.053 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, Grok 4.5 is about 1.7x cheaper ($0.032 vs $0.053). GPT-6 Astra is faster on real-world issues: a median task takes 2m 13s against 3m 9s. Both finished every task on it. Reasons to pick Grok 4.5 anyway: it is cheaper per task ($0.032 vs $0.053) and it leads on real-world issues (C- to D).
Changed since W32: GPT-6 Astra has one graded week under this version (W40); Grok 4.5: real-world issues usage 8.0% to 6.9% of the weekly limit.
| Dimension | GPT-6 Astra | Grok 4.5 | Advantage |
|---|---|---|---|
| Capability | 43% | 60% | +17% (Grok 4.5 leads) |
| Median task time | 2m 13s | 3m 9s | 56s faster (GPT-6 Astra leads) |
| Approx. task cost | $0.052 / task | $0.032 / task | $0.021 / task lower (Grok 4.5 leads) |
GPT-6 Astra: 17.0% of ChatGPT Plus (112.0% / 5h, 17.0% / 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 Astra has run this suite, so there is no head-to-head yet.
| Dimension | GPT-6 Astra | Grok 4.5 | Advantage |
|---|---|---|---|
| Capability | 74% | 59% | +15% (GPT-6 Astra leads) |
| Median task time | 2m 40s | 3m 40s | 1m 0s faster (GPT-6 Astra leads) |
| Approx. task cost | $0.046 / task | $0.031 / task | $0.015 / task lower (Grok 4.5 leads) |
GPT-6 Astra: 1.0% of ChatGPT Plus (7.2% / 5h, 1.0% / 1w) 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 Astra or Grok 4.5?
Grok 4.5 clears higher: tier 4 of 5 versus tier 2 for GPT-6 Astra on real-world@v3, our private suite of real-world coding problems. Latest measurement 2026-09-28.
Which is cheaper per task, GPT-6 Astra or Grok 4.5?
GPT-6 Astra used 22% of ChatGPT Plus's weekly limit per pass, $0.053 per task at the listed price; at the ~$100 tier the board defaults to that is an estimated ~4.4% of ChatGPT Pro 5x's weekly limit (est, about $0.053 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, Grok 4.5 is about 1.7x cheaper ($0.032 vs $0.053).
What do GPT-6 Astra and Grok 4.5 cost a month?
GPT-6 Astra 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).