Claude Opus 5.5 vs GPT-5.6 Sol
Claude Opus 5.5 leads overall, C+ to C-. Claude Opus 5.5 is about 3.0x cheaper per task. By suite, real-world issues is even at C- and spec planning is even at C+. The data gives no reason to pick GPT-5.6 Sol over Claude Opus 5.5 this week.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-5.6 Sol vs Claude Opus 5.5
Claude Opus 5.5 leads overall, C+ to C-. By suite: real-world issues is even at C- (60% vs 60% capability); spec planning is even at C+ (69% vs 68% capability); Claude Opus 5.5 takes vibe coding, B to D+ (85% vs 51% capability). Claude Opus 5.5 used 1% of Claude Max 5x's weekly limit per pass, $0.012 per task at the listed price. GPT-5.6 Sol used 3% of ChatGPT Pro 5x's weekly limit per pass, $0.036 per task at the listed price. Per task, Claude Opus 5.5 is about 3.0x cheaper ($0.012 vs $0.036). Claude Opus 5.5 is faster on real-world issues: a median task takes 2m 18s against 3m 13s. Both finished every task on it. The data gives no reason to pick GPT-5.6 Sol over Claude Opus 5.5 this week.
Changed since W38: GPT-5.6 Sol: vibe coding C- to D+.
| Dimension | Claude Opus 5.5 | GPT-5.6 Sol | Advantage |
|---|---|---|---|
| Capability | 60% | 60% | Even |
| Median task time | 2m 18s | 3m 13s | 55s faster (Claude Opus 5.5 leads) |
| Approx. task cost | $0.015 / task | $0.031 / task | $0.015 / task lower (Claude Opus 5.5 leads) |
Claude Opus 5.5: 16.0% of Claude Max 5x (16.0% / 5h, 1.0% / 1w) per run. Its weekly limit holds about 14.6 of the week's 33.6 5h windows. GPT-5.6 Sol: 2.0% of ChatGPT Pro 5x (2.0% / 1w) per run. Each figure is a share of that agent's own plan, so there is no delta to draw.
| Dimension | Claude Opus 5.5 | GPT-5.6 Sol | Advantage |
|---|---|---|---|
| Capability | 69% | 68% | +1% (Claude Opus 5.5 leads) |
| Median task time | 3m 45s | 6m 0s | 2m 14s faster (Claude Opus 5.5 leads) |
| Approx. task cost | $0.010 / task | $0.057 / task | $0.047 / task lower (Claude Opus 5.5 leads) |
Claude Opus 5.5: 6.0% of Claude Max 5x (6.0% / 5h) per run. Its weekly limit holds about 14.6 of the week's 33.6 5h windows. GPT-5.6 Sol: 1.0% of ChatGPT Pro 5x (1.0% / 1w) per run. Each figure is a share of that agent's own plan, so there is no delta to draw.
| Dimension | Claude Opus 5.5 | GPT-5.6 Sol | Advantage |
|---|---|---|---|
| Capability | 85% | 51% | +34% (Claude Opus 5.5 leads) |
| Median task time | 2m 27s | 3m 56s | 1m 30s faster (Claude Opus 5.5 leads) |
| Approx. task cost | $0.046 / task | $0.092 / task | $0.046 / task lower (Claude Opus 5.5 leads) |
Claude Opus 5.5: 0.8% of Claude Max 5x (0.8% / 5h, 0.2% / 1w) per good solve. Its weekly limit holds about 14.6 of the week's 33.6 5h windows. GPT-5.6 Sol: 0.4% of ChatGPT Pro 5x (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, Claude Opus 5.5 or GPT-5.6 Sol?
They are even on our ladder: both clear tier 4 of 5 at 60% capability on real-world@v3, our private suite of real-world coding problems. Latest measurement 2026-09-23.
Which is cheaper per task, Claude Opus 5.5 or GPT-5.6 Sol?
Claude Opus 5.5 used 1% of Claude Max 5x's weekly limit per pass, $0.012 per task at the listed price. GPT-5.6 Sol used 3% of ChatGPT Pro 5x's weekly limit per pass, $0.036 per task at the listed price. Per task, Claude Opus 5.5 is about 3.0x cheaper ($0.012 vs $0.036).
What do Claude Opus 5.5 and GPT-5.6 Sol cost a month?
Claude Opus 5.5 runs on Claude Max 5x at $100/month (public price as of 2026-07-27). GPT-5.6 Sol runs on ChatGPT Pro 5x at $100/month (public price as of 2026-09-05).