Claude Fable 5 vs GPT-6 Sol
Claude Fable 5 was superseded by Claude Fable 5.1. 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 Fable 5 leads overall, C to D+. GPT-6 Sol is about 14x cheaper per task. By suite, Claude Fable 5 takes real-world issues (C- to D-) and spec planning is even at C. Take GPT-6 Sol anyway when you want the side that is cheaper per task.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 Fable 5
Claude Fable 5 leads overall, C to D+. By suite: Claude Fable 5 takes real-world issues, C- to D- (60% vs 38% capability); spec planning is even at C (63% vs 64% capability); Claude Fable 5 takes vibe coding, C+ to D+ (74% vs 51% capability). Claude Fable 5 used 7% of Claude Max 20x's weekly limit per pass, $0.169 per task at the listed price; at the ~$100 tier the board defaults to that is an estimated ~14% of Claude Max 5x's weekly limit (est, about $0.169 per task). 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, GPT-6 Sol is about 14x cheaper ($0.012 vs $0.169). Claude Fable 5 is faster on real-world issues: a median task takes 2m 37s against 2m 44s. Both finished every task on it. Reasons to pick GPT-6 Sol anyway: it is cheaper per task ($0.012 vs $0.169).
Changed since W35: Claude Fable 5: real-world issues C+ to C-, vibe coding C to C+.
| Dimension | Claude Fable 5 | GPT-6 Sol | Advantage |
|---|---|---|---|
| Capability | 60% | 38% | +22% (Claude Fable 5 leads) |
| Median task time | 2m 37s | 2m 44s | 7s faster (Claude Fable 5 leads) |
| Approx. task cost | $0.153 / task | $0.012 / task | $0.141 / task lower (GPT-6 Sol leads) |
Claude Fable 5: 33.0% of Claude Max 20x (33.0% / 5h, 5.0% / 1w) per run. Its weekly limit holds about 7 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 Fable 5 | GPT-6 Sol | Advantage |
|---|---|---|---|
| Capability | 63% | 64% | +1% (GPT-6 Sol leads) |
| Median task time | 5m 32s | 2m 23s | 3m 9s faster (GPT-6 Sol leads) |
| Approx. task cost | $0.230 / task | $0.011 / task | $0.218 / task lower (GPT-6 Sol leads) |
Claude Fable 5: 10.0% of Claude Max 20x (10.0% / 5h, 2.0% / 1w) per run. Its weekly limit holds about 7 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 Fable 5 | GPT-6 Sol | Advantage |
|---|---|---|---|
| Capability | 74% | 51% | +23% (Claude Fable 5 leads) |
| Median task time | 5m 28s | 3m 4s | 2m 24s faster (GPT-6 Sol leads) |
| Approx. task cost | $0.184 / task | $0.018 / task | $0.166 / task lower (GPT-6 Sol leads) |
Claude Fable 5: 2.8% of Claude Max 20x (2.8% / 5h, 0.4% / 1w) per good solve. Its weekly limit holds about 7 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 Fable 5 or GPT-6 Sol?
Claude Fable 5 clears higher: tier 4 of 5 versus tier 1 for GPT-6 Sol on real-world@v3, our private suite of real-world coding problems. Latest measurement 2026-08-30.
Which is cheaper per task, Claude Fable 5 or GPT-6 Sol?
Claude Fable 5 used 7% of Claude Max 20x's weekly limit per pass, $0.169 per task at the listed price; at the ~$100 tier the board defaults to that is an estimated ~14% of Claude Max 5x's weekly limit (est, about $0.169 per task). 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, GPT-6 Sol is about 14x cheaper ($0.012 vs $0.169).
What do Claude Fable 5 and GPT-6 Sol cost a month?
Claude Fable 5 runs on Claude Max 20x at $200/month (public price as of 2026-08-05). GPT-6 Sol runs on ChatGPT Plus at $20/month (public price as of 2026-07-20).