GPT-5.6 Sol vs Composer 2.5
GPT-5.6 Sol was superseded by GPT-6.1 Sol. 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-5.6 Sol leads overall, C- to D. Composer 2.5 is about 1.7x cheaper per task. By suite, real-world issues is even at C- and GPT-5.6 Sol takes spec planning (C+ to D). Take Composer 2.5 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: Composer 2.5 vs GPT-5.6 Sol
GPT-5.6 Sol leads overall, C- to D. By suite: real-world issues is even at C- (60% vs 57% capability); GPT-5.6 Sol takes spec planning, C+ to D (68% vs 48% capability); GPT-5.6 Sol takes vibe coding, D+ to F (51% vs 23% capability). GPT-5.6 Sol used 3% of ChatGPT Pro 5x's weekly limit per pass, $0.036 per task at the listed price. Composer 2.5 used 2.0% of Cursor Pro's monthly limit per pass, $0.021 per task at the listed price. Per task, Composer 2.5 is about 1.7x cheaper ($0.021 vs $0.036). Composer 2.5 is faster on real-world issues: a median task takes 1m 34s against 3m 13s. Both finished every task on it. Reasons to pick Composer 2.5 anyway: it is cheaper per task ($0.021 vs $0.036) and it is faster on real-world issues (1m 34s vs 3m 13s median).
Changed since the previous graded week: GPT-5.6 Sol: vibe coding C- to D+; Composer 2.5: real-world issues D+ to C-.
| Dimension | GPT-5.6 Sol | Composer 2.5 | Advantage |
|---|---|---|---|
| Capability | 60% | 57% | +3% (GPT-5.6 Sol leads) |
| Median task time | 3m 13s | 1m 34s | 1m 39s faster (Composer 2.5 leads) |
| Approx. task cost | $0.031 / task | $0.021 / task | $0.010 / task lower (Composer 2.5 leads) |
GPT-5.6 Sol: 2.0% of ChatGPT Pro 5x (2.0% / 1w) per run. Composer 2.5: 1.6% of Cursor Pro (1.6% / 1m) 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 | Composer 2.5 | Advantage |
|---|---|---|---|
| Capability | 68% | 48% | +20% (GPT-5.6 Sol leads) |
| Median task time | 6m 0s | 1m 8s | 4m 52s faster (Composer 2.5 leads) |
| Approx. task cost | $0.057 / task | $0.022 / task | $0.035 / task lower (Composer 2.5 leads) |
GPT-5.6 Sol: 1.0% of ChatGPT Pro 5x (1.0% / 1w) per run. 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-5.6 Sol | Composer 2.5 | Advantage |
|---|---|---|---|
| Capability | 51% | 23% | +28% (GPT-5.6 Sol leads) |
| Median task time | 3m 56s | 1m 37s | 2m 20s faster (Composer 2.5 leads) |
| Approx. task cost | $0.092 / task | $0.022 / task | $0.070 / task lower (Composer 2.5 leads) |
GPT-5.6 Sol: 0.4% of ChatGPT Pro 5x (0.4% / 1w) per good solve. Composer 2.5: 0.1% of Cursor Pro (0.1% / 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-5.6 Sol or Composer 2.5?
GPT-5.6 Sol clears higher: tier 4 of 5 versus tier 1 for Composer 2.5 on real-world@v3, our private suite of real-world coding problems. Latest measurement 2026-09-21.
Which is cheaper per task, GPT-5.6 Sol or Composer 2.5?
GPT-5.6 Sol used 3% of ChatGPT Pro 5x's weekly limit per pass, $0.036 per task at the listed price. Composer 2.5 used 2.0% of Cursor Pro's monthly limit per pass, $0.021 per task at the listed price. Per task, Composer 2.5 is about 1.7x cheaper ($0.021 vs $0.036).
What do GPT-5.6 Sol and Composer 2.5 cost a month?
GPT-5.6 Sol runs on ChatGPT Pro 5x at $100/month (public price as of 2026-09-05). Composer 2.5 runs on Cursor Pro at $20/month (public price as of 2026-07-20).