Claude Sonnet 5 vs GPT-6 Sol
GPT-6 Sol leads overall, D+ to D. The two cost about the same per task. By suite, Claude Sonnet 5 takes real-world issues (D+ to D-) and GPT-6 Sol takes spec planning (C to D). Take Claude Sonnet 5 anyway when you want the side that is 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: GPT-6 Sol vs Claude Sonnet 5
GPT-6 Sol leads overall, D+ to D. By suite: Claude Sonnet 5 takes real-world issues, D+ to D- (50% vs 38% capability); GPT-6 Sol takes spec planning, C to D (64% vs 42% capability); vibe coding is even at D+ (51% vs 51% capability). Claude Sonnet 5 used 1% of Claude Max 5x's weekly limit per pass, $0.012 per task at the listed price. 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). Per task the two cost about the same ($0.012 vs $0.012). GPT-6 Sol is faster on real-world issues: a median task takes 2m 44s against 2m 55s. Both finished every task on it. Reasons to pick Claude Sonnet 5 anyway: it leads on real-world issues (D+ to D-).
Changed since W32: Claude Sonnet 5: real-world issues F to D+.
| Dimension | Claude Sonnet 5 | GPT-6 Sol | Advantage |
|---|---|---|---|
| Capability | 50% | 38% | +12% (Claude Sonnet 5 leads) |
| Median task time | 2m 55s | 2m 44s | 10s faster (GPT-6 Sol leads) |
| Approx. task cost | $0.015 / task | $0.012 / task | $0.003 / task lower (GPT-6 Sol leads) |
Claude Sonnet 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-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. Each figure is a share of that agent's own plan, so there is no delta to draw.
| Dimension | Claude Sonnet 5 | GPT-6 Sol | Advantage |
|---|---|---|---|
| Capability | 42% | 64% | +22% (GPT-6 Sol leads) |
| Median task time | 4m 20s | 2m 23s | 1m 57s faster (GPT-6 Sol leads) |
| Approx. task cost | $0.010 / task | $0.011 / task | $0.001 / task lower (Claude Sonnet 5 leads) |
Claude Sonnet 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-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. Each figure is a share of that agent's own plan, so there is no delta to draw.
| Dimension | Claude Sonnet 5 | GPT-6 Sol | Advantage |
|---|---|---|---|
| Capability | 51% | 51% | Even |
| Median task time | 4m 26s | 3m 4s | 1m 22s faster (GPT-6 Sol leads) |
| Approx. task cost | $0.016 / task | $0.018 / task | $0.002 / task lower (Claude Sonnet 5 leads) |
Claude Sonnet 5: 2.4% of Claude Max 5x (2.4% / 5h) per good solve. Its weekly limit holds about 14.6 of the week's 33.6 5h windows. 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. 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 Sol?
Claude Sonnet 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 2026-09-21.
Which is cheaper per task, Claude Sonnet 5 or GPT-6 Sol?
Claude Sonnet 5 used 1% of Claude Max 5x's weekly limit per pass, $0.012 per task at the listed price. 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). Per task the two cost about the same ($0.012 vs $0.012).
What do Claude Sonnet 5 and GPT-6 Sol cost a month?
Claude Sonnet 5 runs on Claude Max 5x at $100/month (public price as of 2026-07-20). GPT-6 Sol runs on ChatGPT Plus at $20/month (public price as of 2026-07-20).