GPT-5.6 Terra 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Grok 4.5 was superseded by Grok 4.7.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.
Grok 4.5 leads overall, C- to D. GPT-5.6 Terra is about 1.6x cheaper per task. By suite, Grok 4.5 takes real-world issues (C- to D+) and vibe coding (C- to F). Take GPT-5.6 Terra 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-5.6 Terra
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 34% capability). Only GPT-5.6 Terra has run spec planning. GPT-5.6 Terra used 8% of ChatGPT Plus's weekly limit per pass, $0.019 per task at the listed price; at the ~$100 tier the board defaults to that is an estimated ~1.6% of ChatGPT Pro 5x's weekly limit (est, about $0.019 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-5.6 Terra is about 1.6x cheaper ($0.019 vs $0.032). GPT-5.6 Terra is faster on real-world issues: a median task takes 2m 18s against 3m 9s. Both finished every task on it. Reasons to pick GPT-5.6 Terra anyway: it is cheaper per task ($0.019 vs $0.032) and it is faster on real-world issues (2m 18s vs 3m 9s median).
Changed since the previous graded week: GPT-5.6 Terra: real-world issues D to D+, real-world issues usage 9.2% to 7% of the weekly limit, spec planning C- to D+, spec planning usage 2.0% to 1% of the weekly limit, vibe coding F to D, vibe coding usage 0.5% to 0.6% of the weekly limit; Grok 4.5: real-world issues usage 8.0% to 6.9% of the weekly limit.
| Dimension | GPT-5.6 Terra | Grok 4.5 | Advantage |
|---|---|---|---|
| Capability | 50% | 60% | +10% (Grok 4.5 leads) |
| Median task time | 2m 18s | 3m 9s | 52s faster (GPT-5.6 Terra leads) |
| Approx. task cost | $0.021 / task | $0.032 / task | $0.010 / task lower (GPT-5.6 Terra leads) |
GPT-5.6 Terra: 7.0% of ChatGPT Plus (46.0% / 5h, 7.0% / 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-5.6 Terra has run this suite, so there is no head-to-head yet.
| Dimension | GPT-5.6 Terra | Grok 4.5 | Advantage |
|---|---|---|---|
| Capability | 34% | 59% | +25% (Grok 4.5 leads) |
| Median task time | 2m 47s | 3m 40s | 52s faster (GPT-5.6 Terra leads) |
| Approx. task cost | $0.028 / task | $0.031 / task | $0.003 / task lower (GPT-5.6 Terra leads) |
GPT-5.6 Terra: 0.6% of ChatGPT Plus (3.0% / 5h, 0.6% / 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-5.6 Terra or Grok 4.5?
Grok 4.5 clears higher: tier 4 of 5 versus tier 2 for GPT-5.6 Terra on real-world@v3, our private suite of real-world coding problems. Latest measurement 2026-09-28.
Which is cheaper per task, GPT-5.6 Terra or Grok 4.5?
GPT-5.6 Terra used 8% of ChatGPT Plus's weekly limit per pass, $0.019 per task at the listed price; at the ~$100 tier the board defaults to that is an estimated ~1.6% of ChatGPT Pro 5x's weekly limit (est, about $0.019 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-5.6 Terra is about 1.6x cheaper ($0.019 vs $0.032).
What do GPT-5.6 Terra and Grok 4.5 cost a month?
GPT-5.6 Terra 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).