Claude Fable 5 vs GPT-6.1 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Claude Fable 5 was superseded by Claude Fable 5.1.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.
Both grade C overall. GPT-6.1 Sol is about 12x cheaper per task. By suite, real-world issues is even at C- and GPT-6.1 Sol takes spec planning (C+ to C). Both agents run the same private suite cut headless through their own tools, each on its own subscription.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 Fable 5
Both grade C overall. By suite: real-world issues is even at C- (60% vs 57% capability); GPT-6.1 Sol takes spec planning, C+ to C (73% vs 63% capability); vibe coding is even at C+ (74% vs 72% 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-6.1 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 12x cheaper ($0.015 vs $0.169). Claude Fable 5 is faster on real-world issues: a median task takes 2m 37s against 3m 26s. Both finished every task on it.
Changed since W35: Claude Fable 5: real-world issues C+ to C-, vibe coding C to C+; GPT-6.1 Sol has one graded week under this version (W40).
| Dimension | Claude Fable 5 | GPT-6.1 Sol | Advantage |
|---|---|---|---|
| Capability | 60% | 57% | +3% (Claude Fable 5 leads) |
| Median task time | 2m 37s | 3m 26s | 49s faster (Claude Fable 5 leads) |
| Approx. task cost | $0.153 / task | $0.012 / task | $0.141 / task lower (GPT-6.1 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-6.1 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 Fable 5 | GPT-6.1 Sol | Advantage |
|---|---|---|---|
| Capability | 63% | 73% | +10% (GPT-6.1 Sol leads) |
| Median task time | 5m 32s | 6m 22s | 50s faster (Claude Fable 5 leads) |
| Approx. task cost | $0.230 / task | $0.023 / task | $0.207 / task lower (GPT-6.1 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-6.1 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 Fable 5 | GPT-6.1 Sol | Advantage |
|---|---|---|---|
| Capability | 74% | 72% | +3% (Claude Fable 5 leads) |
| Median task time | 5m 28s | 4m 55s | 34s faster (GPT-6.1 Sol leads) |
| Approx. task cost | $0.184 / task | $0.018 / task | $0.166 / task lower (GPT-6.1 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-6.1 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 Fable 5 or GPT-6.1 Sol?
Claude Fable 5 clears higher: tier 4 of 5 versus tier 2 for GPT-6.1 Sol on real-world@v3, our private suite of real-world coding problems. Latest measurement 2026-08-30.
Which is cheaper per task, Claude Fable 5 or GPT-6.1 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-6.1 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 12x cheaper ($0.015 vs $0.169).
What do Claude Fable 5 and GPT-6.1 Sol cost a month?
Claude Fable 5 runs on Claude Max 20x at $200/month (public price as of 2026-08-05). GPT-6.1 Sol runs on ChatGPT Plus at $20/month (public price as of 2026-07-20).