Claude Opus 5 vs GPT-5.6 Sol
Claude Opus 5 was superseded by Claude Opus 5.5. GPT-5.6 Sol was superseded by GPT-6.1 Sol.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.
Claude Opus 5 leads overall, C to C-. Claude Opus 5 is about 1.5x cheaper per task. By suite, real-world issues is even at C- and GPT-5.6 Sol takes spec planning (C+ to C). Take GPT-5.6 Sol anyway when you want the side that is ahead on spec planning.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
Claude Opus 5 leads overall, C to C-. By suite: real-world issues is even at C- (57% vs 60% capability); GPT-5.6 Sol takes spec planning, C+ to C (68% vs 66% capability); Claude Opus 5 takes vibe coding, C+ to D+ (72% vs 51% capability). Claude Opus 5 used 2% of Claude Max 5x's weekly limit per pass, $0.024 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 is about 1.5x cheaper ($0.024 vs $0.036). Claude Opus 5 is faster on real-world issues: a median task takes 1m 56s against 3m 13s. Both finished every task on it. Reasons to pick GPT-5.6 Sol anyway: it leads on spec planning (C+ to C).
Changed since the previous graded week: Claude Opus 5: real-world issues usage 3% to 1% of the weekly limit; GPT-5.6 Sol: vibe coding C- to D+.
| Dimension | Claude Opus 5 | GPT-5.6 Sol | Advantage |
|---|---|---|---|
| Capability | 57% | 60% | +3% (GPT-5.6 Sol leads) |
| Median task time | 1m 56s | 3m 13s | 1m 17s faster (Claude Opus 5 leads) |
| Approx. task cost | $0.015 / task | $0.031 / task | $0.015 / task lower (Claude Opus 5 leads) |
Claude Opus 5: 21.0% of Claude Max 5x (21.0% / 5h, 1.0% / 1w) per run. Its weekly limit holds about 13.8 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 | GPT-5.6 Sol | Advantage |
|---|---|---|---|
| Capability | 66% | 68% | +3% (GPT-5.6 Sol leads) |
| Median task time | 2m 9s | 6m 0s | 3m 51s faster (Claude Opus 5 leads) |
| Approx. task cost | $0.057 / task | $0.057 / task | Even |
Claude Opus 5: 6.0% of Claude Max 5x (6.0% / 5h, 1.0% / 1w) per run. Its weekly limit holds about 13.8 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 | GPT-5.6 Sol | Advantage |
|---|---|---|---|
| Capability | 72% | 51% | +21% (Claude Opus 5 leads) |
| Median task time | 2m 51s | 3m 56s | 1m 5s faster (Claude Opus 5 leads) |
| Approx. task cost | $0.011 / task | $0.092 / task | $0.081 / task lower (Claude Opus 5 leads) |
Claude Opus 5: 1.6% of Claude Max 5x (1.6% / 5h) per good solve. Its weekly limit holds about 13.8 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 or GPT-5.6 Sol?
GPT-5.6 Sol clears higher: tier 4 of 5 versus tier 2 for Claude Opus 5 on real-world@v3, our private suite of real-world coding problems. Latest measurement 2026-09-21.
Which is cheaper per task, Claude Opus 5 or GPT-5.6 Sol?
Claude Opus 5 used 2% of Claude Max 5x's weekly limit per pass, $0.024 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 is about 1.5x cheaper ($0.024 vs $0.036).
What do Claude Opus 5 and GPT-5.6 Sol cost a month?
Claude Opus 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).