GPT-6 Sol vs Composer 2.5
GPT-6 Sol leads overall, D+ to D-. GPT-6 Sol is about 1.9x cheaper per task. By suite, Composer 2.5 takes real-world issues (D+ to D-) and GPT-6 Sol takes spec planning (C to D). Take Composer 2.5 anyway when you want the side that is faster on real-world issues 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: Composer 2.5 vs GPT-6 Sol
GPT-6 Sol leads overall, D+ to D-. By suite: Composer 2.5 takes real-world issues, D+ to D- (50% vs 38% capability); GPT-6 Sol takes spec planning, C to D (64% vs 45% capability); GPT-6 Sol takes vibe coding, D+ to F (51% vs 23% capability). GPT-6 Sol used 5% of ChatGPT Plus's weekly limit per pass, $0.012 per task at the listed price; at the ~$100 tier the board defaults to that is an estimated ~1% of ChatGPT Pro 5x's weekly limit (est, about $0.012 per task). Composer 2.5 used 2.1% of Cursor Pro's monthly limit per pass, $0.023 per task at the listed price. Per task, GPT-6 Sol is about 1.9x cheaper ($0.012 vs $0.023). Composer 2.5 is faster on real-world issues: a median task takes 1m 21s against 2m 44s. Both finished every task on it. Reasons to pick Composer 2.5 anyway: it is faster on real-world issues (1m 21s vs 2m 44s median) and it leads on real-world issues (D+ to D-).
Changed since W38: Composer 2.5: spec planning D- to D.
| Dimension | GPT-6 Sol | Composer 2.5 | Advantage |
|---|---|---|---|
| Capability | 38% | 50% | +12% (Composer 2.5 leads) |
| Median task time | 2m 44s | 1m 21s | 1m 23s faster (Composer 2.5 leads) |
| Approx. task cost | $0.012 / task | $0.023 / task | $0.010 / task lower (GPT-6 Sol leads) |
GPT-6 Sol: 4.0% of ChatGPT Plus (37.0% / 5h, 4.0% / 1w) per run. Its weekly limit holds about 6 of the week's 33.6 5h windows. Composer 2.5: 1.7% of Cursor Pro (1.7% / 1m) per run. Each figure is a share of that agent's own plan, so there is no delta to draw.
| Dimension | GPT-6 Sol | Composer 2.5 | Advantage |
|---|---|---|---|
| Capability | 64% | 45% | +19% (GPT-6 Sol leads) |
| Median task time | 2m 23s | 1m 50s | 32s faster (Composer 2.5 leads) |
| Approx. task cost | $0.011 / task | $0.022 / task | $0.011 / task lower (GPT-6 Sol leads) |
GPT-6 Sol: 1.0% of ChatGPT Plus (8.0% / 5h, 1.0% / 1w) per run. Its weekly limit holds about 6 of the week's 33.6 5h windows. Composer 2.5: 0.4% of Cursor Pro (0.4% / 1m) per run. Each figure is a share of that agent's own plan, so there is no delta to draw.
| Dimension | GPT-6 Sol | Composer 2.5 | Advantage |
|---|---|---|---|
| Capability | 51% | 23% | +28% (GPT-6 Sol leads) |
| Median task time | 3m 4s | 1m 55s | 1m 10s faster (Composer 2.5 leads) |
| Approx. task cost | $0.018 / task | $0.031 / task | $0.012 / task lower (GPT-6 Sol leads) |
GPT-6 Sol: 0.4% of ChatGPT Plus (2.4% / 5h, 0.4% / 1w) per good solve. Its weekly limit holds about 6 of the week's 33.6 5h windows. Composer 2.5: 0.2% of Cursor Pro (0.2% / 1m) 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 Sol or Composer 2.5?
Composer 2.5 clears higher: tier 2 of 5 versus tier 1 for GPT-6 Sol on real-world@v3, our private suite of real-world coding problems. Latest measurement 2026-09-23.
Which is cheaper per task, GPT-6 Sol or Composer 2.5?
GPT-6 Sol used 5% of ChatGPT Plus's weekly limit per pass, $0.012 per task at the listed price; at the ~$100 tier the board defaults to that is an estimated ~1% of ChatGPT Pro 5x's weekly limit (est, about $0.012 per task). Composer 2.5 used 2.1% of Cursor Pro's monthly limit per pass, $0.023 per task at the listed price. Per task, GPT-6 Sol is about 1.9x cheaper ($0.012 vs $0.023).
What do GPT-6 Sol and Composer 2.5 cost a month?
GPT-6 Sol runs on ChatGPT Plus at $20/month (public price as of 2026-07-20). Composer 2.5 runs on Cursor Pro at $20/month (public price as of 2026-07-20).