Claude Fable 5 vs Claude Fable 5.1
Claude Fable 5 was superseded by Claude Fable 5.1.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 5.1 leads overall, B- to C. Claude Fable 5.1 is about 1.7x cheaper per task. By suite, Claude Fable 5.1 takes real-world issues (B+ to C-) and spec planning (C+ to C). Take Claude Fable 5 anyway when you want the side that is 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: Claude Fable 5.1 vs Claude Fable 5
Claude Fable 5.1 leads overall, B- to C. By suite: Claude Fable 5.1 takes real-world issues, B+ to C- (87% vs 60% capability); Claude Fable 5.1 takes spec planning, C+ to C (71% vs 63% capability); vibe coding is even at C+ (74% vs 74% 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). Claude Fable 5.1 used 8% of Claude Max 5x's weekly limit per pass, $0.097 per task at the listed price. Per task, Claude Fable 5.1 is about 1.7x cheaper ($0.097 vs $0.169). Claude Fable 5 is faster on real-world issues: a median task takes 2m 37s against 3m 38s. Both finished every task on it. Reasons to pick Claude Fable 5 anyway: it is faster on real-world issues (2m 37s vs 3m 38s median).
Changed since the previous graded week: Claude Fable 5: real-world issues C+ to C-, vibe coding C to C+; Claude Fable 5.1: real-world issues D+ to B+, real-world issues usage 7% to 5% of the weekly limit, spec planning usage 4% to 3% of the weekly limit, vibe coding C- to C+, vibe coding usage 0.6% to 0.4% of the weekly limit.
| Dimension | Claude Fable 5 | Claude Fable 5.1 | Advantage |
|---|---|---|---|
| Capability | 60% | 87% | +27% (Claude Fable 5.1 leads) |
| Median task time | 2m 37s | 3m 38s | 1m 1s faster (Claude Fable 5 leads) |
| Approx. task cost | $0.153 / task | $0.077 / task | $0.077 / task lower (Claude Fable 5.1 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. Claude Fable 5.1: 64.0% of Claude Max 5x (64.0% / 5h, 5.0% / 1w) per run. Its weekly limit holds about 13.8 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.
Work per window: Claude Fable 5 443 vs Claude Fable 5.1 228 suite runs per month (Claude Fable 5 leads); per plan-dollar: 2.21 vs 2.28 (Claude Fable 5.1 leads). Work figures compare outputs, so unlike quota shares they are comparable across plans.
| Dimension | Claude Fable 5 | Claude Fable 5.1 | Advantage |
|---|---|---|---|
| Capability | 63% | 71% | +8% (Claude Fable 5.1 leads) |
| Median task time | 5m 32s | 8m 55s | 3m 23s faster (Claude Fable 5 leads) |
| Approx. task cost | $0.230 / task | $0.172 / task | $0.057 / task lower (Claude Fable 5.1 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. Claude Fable 5.1: 33.0% of Claude Max 5x (33.0% / 5h, 3.0% / 1w) per run. Its weekly limit holds about 13.8 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.
Work per window: Claude Fable 5 1461 vs Claude Fable 5.1 443 suite runs per month (Claude Fable 5 leads); per plan-dollar: 7.30 vs 4.43 (Claude Fable 5 leads). Work figures compare outputs, so unlike quota shares they are comparable across plans.
| Dimension | Claude Fable 5 | Claude Fable 5.1 | Advantage |
|---|---|---|---|
| Capability | 74% | 74% | Even |
| Median task time | 5m 28s | 4m 14s | 1m 15s faster (Claude Fable 5.1 leads) |
| Approx. task cost | $0.184 / task | $0.092 / task | $0.092 / task lower (Claude Fable 5.1 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. Claude Fable 5.1: 4.2% of Claude Max 5x (4.2% / 5h, 0.4% / 1w) per good solve. Its weekly limit holds about 13.8 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.
Work per window: Claude Fable 5 5218 vs Claude Fable 5.1 3479 good solves per month (Claude Fable 5 leads); per plan-dollar: 26.09 vs 34.79 (Claude Fable 5.1 leads). Work figures compare outputs, so unlike quota shares they are comparable across plans.
Grades and deltas are comparable only within a suite version. See methodology.
Frequently asked questions
Which is better for coding, Claude Fable 5 or Claude Fable 5.1?
Both clear tier 4 of 5, but Claude Fable 5.1 scores higher on capability: 87% versus 60% 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 Claude Fable 5.1?
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). Claude Fable 5.1 used 8% of Claude Max 5x's weekly limit per pass, $0.097 per task at the listed price. Per task, Claude Fable 5.1 is about 1.7x cheaper ($0.097 vs $0.169).
Which gives more coding work per dollar, Claude Fable 5 or Claude Fable 5.1?
Claude Fable 5.1 delivers more benchmark work per subscription dollar: 2.28 suite runs per plan-dollar versus 2.21 for Claude Fable 5 (at $100/month priced 2026-07-27, and $200/month priced 2026-08-05). Work figures compare outputs, so unlike raw quota shares they are comparable across plans.
What do Claude Fable 5 and Claude Fable 5.1 cost a month?
Claude Fable 5 runs on Claude Max 20x at $200/month (public price as of 2026-08-05). Claude Fable 5.1 runs on Claude Max 5x at $100/month (public price as of 2026-07-27).