GPT-6.1 Sol vs GPT-6 Astra
Both grade C overall. GPT-6.1 Sol is about 3.7x cheaper per task. By suite, GPT-6.1 Sol takes real-world issues (C- to D) and spec planning is even at C+. 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 Astra vs GPT-6.1 Sol
Both grade C overall. By suite: GPT-6.1 Sol takes real-world issues, C- to D (57% vs 43% capability); spec planning is even at C+ (73% vs 74% capability); vibe coding is even at C+ (72% vs 74% capability). GPT-6.1 Sol used 6% of ChatGPT Plus's weekly limit per pass, $0.015 per task at the listed price; at the ~$100 tier the board defaults to that is an estimated ~1.2% of ChatGPT Pro 5x's weekly limit (est, about $0.015 per task). 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). Per task, GPT-6.1 Sol is about 3.7x cheaper ($0.015 vs $0.053). GPT-6 Astra is faster on real-world issues: a median task takes 2m 13s against 3m 26s. Both finished every task on it.
| Dimension | GPT-6.1 Sol | GPT-6 Astra | Advantage |
|---|---|---|---|
| Capability | 57% | 43% | +13% (GPT-6.1 Sol leads) |
| Median task time | 3m 26s | 2m 13s | 1m 13s faster (GPT-6 Astra leads) |
| Approx. task cost | $0.012 / task | $0.052 / task | $0.040 / task lower (GPT-6.1 Sol leads) |
GPT-6.1 Sol: 4.0% of ChatGPT Plus (28.0% / 5h, 4.0% / 1w) per run. Its weekly limit holds about 6 of the week's 33.6 5h windows. 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. Each figure is a share of that agent's own plan, so there is no delta to draw.
| Dimension | GPT-6.1 Sol | GPT-6 Astra | Advantage |
|---|---|---|---|
| Capability | 73% | 74% | +1% (GPT-6 Astra leads) |
| Median task time | 6m 22s | 3m 5s | 3m 17s faster (GPT-6 Astra leads) |
| Approx. task cost | $0.023 / task | $0.057 / task | $0.034 / task lower (GPT-6.1 Sol leads) |
GPT-6.1 Sol: 2.0% of ChatGPT Plus (9.0% / 5h, 2.0% / 1w) per run. Its weekly limit holds about 6 of the week's 33.6 5h windows. GPT-6 Astra: 5.0% of ChatGPT Plus (27.0% / 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-6.1 Sol | GPT-6 Astra | Advantage |
|---|---|---|---|
| Capability | 72% | 74% | +3% (GPT-6 Astra leads) |
| Median task time | 4m 55s | 2m 40s | 2m 15s faster (GPT-6 Astra leads) |
| Approx. task cost | $0.018 / task | $0.046 / task | $0.028 / task lower (GPT-6.1 Sol leads) |
GPT-6.1 Sol: 0.4% of ChatGPT Plus (2.2% / 5h, 0.4% / 1w) per good solve. Its weekly limit holds about 6 of the week's 33.6 5h windows. 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. 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-6.1 Sol or GPT-6 Astra?
Both clear tier 2 of 5, but GPT-6.1 Sol scores higher on capability: 57% versus 43% on real-world@v3, our private suite of real-world coding problems. Latest measurement 2026-09-30.
Which is cheaper per task, GPT-6.1 Sol or GPT-6 Astra?
GPT-6.1 Sol used 6% of ChatGPT Plus's weekly limit per pass, $0.015 per task at the listed price; at the ~$100 tier the board defaults to that is an estimated ~1.2% of ChatGPT Pro 5x's weekly limit (est, about $0.015 per task). 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). Per task, GPT-6.1 Sol is about 3.7x cheaper ($0.015 vs $0.053).
What do GPT-6.1 Sol and GPT-6 Astra cost a month?
GPT-6.1 Sol runs on ChatGPT Plus at $20/month (public price as of 2026-07-20). GPT-6 Astra runs on ChatGPT Plus at $20/month (public price as of 2026-07-20).