GPT-5.6 Sol vs GPT-6 Astra
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.
| Dimension | GPT-5.6 Sol | GPT-6 Astra | Advantage |
|---|---|---|---|
| Capability | 60% | 57% | +3% (GPT-5.6 Sol leads) |
| Median task time | 2m 50s | 1m 56s | 53s faster (GPT-6 Astra leads) |
| Approx. task cost | $0.039 / task | $0.046 / task | $0.007 / task lower (GPT-5.6 Sol leads) |
GPT-5.6 Sol: 12.6% of ChatGPT Plus (75.5% / 5h, 12.6% / 1w) per run. Its weekly limit holds about 6 of the week's 33.6 5h windows. GPT-6 Astra: 3.0% of ChatGPT Pro $100 (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-5.6 Sol | GPT-6 Astra | Advantage |
|---|---|---|---|
| Capability | 74% | 74% | +0% (GPT-5.6 Sol leads) |
| Median task time | 4m 46s | 4m 0s | 46s faster (GPT-6 Astra leads) |
| Approx. task cost | $0.033 / task | $0.057 / task | $0.025 / task lower (GPT-5.6 Sol leads) |
GPT-5.6 Sol: 2.9% of ChatGPT Plus (17.1% / 5h, 2.9% / 1w) per run. Its weekly limit holds about 6 of the week's 33.6 5h windows. GPT-6 Astra: 1.0% of ChatGPT Pro $100 (1.0% / 1w) per run. Each figure is a share of that agent's own plan, so there is no delta to draw.
| Dimension | GPT-5.6 Sol | GPT-6 Astra | Advantage |
|---|---|---|---|
| Capability | 56% | 61% | +5% (GPT-6 Astra leads) |
| Median task time | 6m 10s | 2m 54s | 3m 16s faster (GPT-6 Astra leads) |
| Approx. task cost | $0.032 / task | $0.046 / task | $0.014 / task lower (GPT-5.6 Sol leads) |
GPT-5.6 Sol: 0.7% of ChatGPT Plus (4.1% / 5h, 0.7% / 1w) per good solve. Its weekly limit holds about 6 of the week's 33.6 5h windows. GPT-6 Astra: 0.2% of ChatGPT Pro $100 (0.2% / 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 Sol or GPT-6 Astra?
GPT-5.6 Sol 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 2026-08-31.
How much do GPT-5.6 Sol and GPT-6 Astra cost?
GPT-5.6 Sol runs on ChatGPT Plus at $20/month (public price as of 2026-07-20). GPT-6 Astra runs on ChatGPT Pro $100 at $100/month (public price as of 2026-09-05).