Claude Sonnet 5 vs GPT-6.1 Sol
Claude Sonnet 5 is no longer on the leaderboard. 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-6.1 Sol leads overall, C to D. GPT-6.1 Sol is about 1.7x cheaper per task. By suite, GPT-6.1 Sol takes real-world issues (C- to D+) and spec planning (C+ to D). The data gives no reason to pick Claude Sonnet 5 over GPT-6.1 Sol 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-6.1 Sol vs Claude Sonnet 5
GPT-6.1 Sol leads overall, C to D. By suite: GPT-6.1 Sol takes real-world issues, C- to D+ (57% vs 53% capability); GPT-6.1 Sol takes spec planning, C+ to D (73% vs 44% capability); GPT-6.1 Sol takes vibe coding, C+ to F (72% vs 31% capability). Claude Sonnet 5 used 2% of Claude Max 5x's weekly limit per pass, $0.024 per task at the listed price. GPT-6.1 Sol used 6% of ChatGPT Plus's weekly limit per pass, $0.015 per task at the listed price; at the ~$100 tier the board defaults to that is an estimated ~1.2% of ChatGPT Pro 5x's weekly limit (est, about $0.015 per task). Per task, GPT-6.1 Sol is about 1.7x cheaper ($0.015 vs $0.024). GPT-6.1 Sol is faster on real-world issues: a median task takes 3m 26s against 3m 35s. Both finished every task on it. The data gives no reason to pick Claude Sonnet 5 over GPT-6.1 Sol this week.
Changed since W39: Claude Sonnet 5: vibe coding D+ to F; GPT-6.1 Sol has one graded week under this version (W40).
| Dimension | Claude Sonnet 5 | GPT-6.1 Sol | Advantage |
|---|---|---|---|
| Capability | 53% | 57% | +3% (GPT-6.1 Sol leads) |
| Median task time | 3m 35s | 3m 26s | 9s faster (GPT-6.1 Sol leads) |
| Approx. task cost | $0.015 / task | $0.012 / task | $0.003 / task lower (GPT-6.1 Sol leads) |
Claude Sonnet 5: 12.0% of Claude Max 5x (12.0% / 5h, 1.0% / 1w) per run. Its weekly limit holds about 13.8 of the week's 33.6 5h windows. GPT-6.1 Sol: 4.0% of ChatGPT Plus (28.0% / 5h, 4.0% / 1w) per run. Its weekly limit holds about 6 of the week's 33.6 5h windows. Each figure is a share of that agent's own plan, so there is no delta to draw.
| Dimension | Claude Sonnet 5 | GPT-6.1 Sol | Advantage |
|---|---|---|---|
| Capability | 44% | 73% | +30% (GPT-6.1 Sol leads) |
| Median task time | 5m 12s | 6m 22s | 1m 10s faster (Claude Sonnet 5 leads) |
| Approx. task cost | $0.057 / task | $0.023 / task | $0.034 / task lower (GPT-6.1 Sol leads) |
Claude Sonnet 5: 5.0% of Claude Max 5x (5.0% / 5h, 1.0% / 1w) per run. Its weekly limit holds about 13.8 of the week's 33.6 5h windows. GPT-6.1 Sol: 2.0% of ChatGPT Plus (9.0% / 5h, 2.0% / 1w) per run. Its weekly limit holds about 6 of the week's 33.6 5h windows. Each figure is a share of that agent's own plan, so there is no delta to draw.
| Dimension | Claude Sonnet 5 | GPT-6.1 Sol | Advantage |
|---|---|---|---|
| Capability | 31% | 72% | +41% (GPT-6.1 Sol leads) |
| Median task time | 4m 31s | 4m 55s | 24s faster (Claude Sonnet 5 leads) |
| Approx. task cost | $0.007 / task | $0.018 / task | $0.012 / task lower (Claude Sonnet 5 leads) |
Claude Sonnet 5: 1.0% of Claude Max 5x (1.0% / 5h) per good solve. Its weekly limit holds about 13.8 of the week's 33.6 5h windows. GPT-6.1 Sol: 0.4% of ChatGPT Plus (2.2% / 5h, 0.4% / 1w) per good solve. Its weekly limit holds about 6 of the week's 33.6 5h windows. 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 Sonnet 5 or GPT-6.1 Sol?
Claude Sonnet 5 clears higher: tier 3 of 5 versus tier 2 for GPT-6.1 Sol on real-world@v3, our private suite of real-world coding problems. Latest measurement 2026-09-28.
Which is cheaper per task, Claude Sonnet 5 or GPT-6.1 Sol?
Claude Sonnet 5 used 2% of Claude Max 5x's weekly limit per pass, $0.024 per task at the listed price. GPT-6.1 Sol used 6% of ChatGPT Plus's weekly limit per pass, $0.015 per task at the listed price; at the ~$100 tier the board defaults to that is an estimated ~1.2% of ChatGPT Pro 5x's weekly limit (est, about $0.015 per task). Per task, GPT-6.1 Sol is about 1.7x cheaper ($0.015 vs $0.024).
What do Claude Sonnet 5 and GPT-6.1 Sol cost a month?
Claude Sonnet 5 runs on Claude Max 5x at $100/month (public price as of 2026-07-20). GPT-6.1 Sol runs on ChatGPT Plus at $20/month (public price as of 2026-07-20).