Claude Haiku 4.5 vs GPT-6.1 Sol
GPT-6.1 Sol leads overall, C to F. Claude Haiku 4.5 is about 1.2x cheaper per task. By suite, GPT-6.1 Sol takes real-world issues (C- to D-) and spec planning (C+ to F). Take Claude Haiku 4.5 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: GPT-6.1 Sol vs Claude Haiku 4.5
GPT-6.1 Sol leads overall, C to F. By suite: GPT-6.1 Sol takes real-world issues, C- to D- (57% vs 37% capability); GPT-6.1 Sol takes spec planning, C+ to F (73% vs 21% capability); GPT-6.1 Sol takes vibe coding, C+ to F (72% vs 22% capability). Claude Haiku 4.5 used 1% of Claude Max 5x's weekly limit per pass, $0.012 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, Claude Haiku 4.5 is about 1.2x cheaper ($0.012 vs $0.015). Claude Haiku 4.5 is faster on real-world issues: a median task takes 3m 8s against 3m 26s. Both finished every task on it. Reasons to pick Claude Haiku 4.5 anyway: it is cheaper per task ($0.012 vs $0.015) and it is faster on real-world issues (3m 8s vs 3m 26s median).
Changed since W39: Claude Haiku 4.5: real-world issues D+ to D-; GPT-6.1 Sol has one graded week under this version (W40).
| Dimension | Claude Haiku 4.5 | GPT-6.1 Sol | Advantage |
|---|---|---|---|
| Capability | 37% | 57% | +20% (GPT-6.1 Sol leads) |
| Median task time | 3m 8s | 3m 26s | 18s faster (Claude Haiku 4.5 leads) |
| Approx. task cost | $0.015 / task | $0.012 / task | $0.003 / task lower (GPT-6.1 Sol leads) |
Claude Haiku 4.5: 8.0% of Claude Max 5x (8.0% / 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 Haiku 4.5 | GPT-6.1 Sol | Advantage |
|---|---|---|---|
| Capability | 21% | 73% | +53% (GPT-6.1 Sol leads) |
| Median task time | 2m 8s | 6m 22s | 4m 14s faster (Claude Haiku 4.5 leads) |
| Approx. task cost | $0.002 / task | $0.023 / task | $0.021 / task lower (Claude Haiku 4.5 leads) |
Claude Haiku 4.5: 1.0% of Claude Max 5x (1.0% / 5h) 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 Haiku 4.5 | GPT-6.1 Sol | Advantage |
|---|---|---|---|
| Capability | 22% | 72% | +50% (GPT-6.1 Sol leads) |
| Median task time | 4m 4s | 4m 55s | 51s faster (Claude Haiku 4.5 leads) |
| Approx. task cost | $0.009 / task | $0.018 / task | $0.010 / task lower (Claude Haiku 4.5 leads) |
Claude Haiku 4.5: 1.3% of Claude Max 5x (1.3% / 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 Haiku 4.5 or GPT-6.1 Sol?
Both clear tier 2 of 5, but GPT-6.1 Sol scores higher on capability: 57% versus 37% on real-world@v3, our private suite of real-world coding problems. Latest measurement 2026-09-28.
Which is cheaper per task, Claude Haiku 4.5 or GPT-6.1 Sol?
Claude Haiku 4.5 used 1% of Claude Max 5x's weekly limit per pass, $0.012 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, Claude Haiku 4.5 is about 1.2x cheaper ($0.012 vs $0.015).
What do Claude Haiku 4.5 and GPT-6.1 Sol cost a month?
Claude Haiku 4.5 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).