Claude Fable 5 vs Claude Sonnet 5
Claude Fable 5 was superseded by Claude Fable 5.1. Claude Sonnet 5 is no longer on the leaderboard. 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. Claude Sonnet 5 is about 7.0x cheaper per task. By suite, Claude Fable 5 takes real-world issues (C- to D+) and spec planning (C to D). Take Claude Sonnet 5 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: Claude Sonnet 5 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 53% capability); Claude Fable 5 takes spec planning, C to D (63% vs 44% capability); Claude Fable 5 takes vibe coding, C+ to F (74% vs 31% 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 Sonnet 5 used 2% of Claude Max 5x's weekly limit per pass, $0.024 per task at the listed price. Per task, Claude Sonnet 5 is about 7.0x cheaper ($0.024 vs $0.169). Claude Fable 5 is faster on real-world issues: a median task takes 2m 37s against 3m 35s. Both finished every task on it. Reasons to pick Claude Sonnet 5 anyway: it is cheaper per task ($0.024 vs $0.169).
Changed since the previous graded week: Claude Fable 5: real-world issues C+ to C-, vibe coding C to C+; Claude Sonnet 5: vibe coding D+ to F.
| Dimension | Claude Fable 5 | Claude Sonnet 5 | Advantage |
|---|---|---|---|
| Capability | 60% | 53% | +7% (Claude Fable 5 leads) |
| Median task time | 2m 37s | 3m 35s | 59s faster (Claude Fable 5 leads) |
| Approx. task cost | $0.153 / task | $0.015 / task | $0.138 / task lower (Claude Sonnet 5 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 Sonnet 5: 12.0% of Claude Max 5x (12.0% / 5h, 1.0% / 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 Sonnet 5 1218 suite runs per month (Claude Sonnet 5 leads); per plan-dollar: 2.21 vs 12.18 (Claude Sonnet 5 leads). Work figures compare outputs, so unlike quota shares they are comparable across plans.
| Dimension | Claude Fable 5 | Claude Sonnet 5 | Advantage |
|---|---|---|---|
| Capability | 63% | 44% | +19% (Claude Fable 5 leads) |
| Median task time | 5m 32s | 5m 12s | 20s faster (Claude Sonnet 5 leads) |
| Approx. task cost | $0.230 / task | $0.057 / task | $0.172 / task lower (Claude Sonnet 5 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 Sonnet 5: 5.0% of Claude Max 5x (5.0% / 5h, 1.0% / 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 Sonnet 5 2922 suite runs per month (Claude Sonnet 5 leads); per plan-dollar: 7.30 vs 29.22 (Claude Sonnet 5 leads). Work figures compare outputs, so unlike quota shares they are comparable across plans.
| Dimension | Claude Fable 5 | Claude Sonnet 5 | Advantage |
|---|---|---|---|
| Capability | 74% | 31% | +43% (Claude Fable 5 leads) |
| Median task time | 5m 28s | 4m 31s | 58s faster (Claude Sonnet 5 leads) |
| Approx. task cost | $0.184 / task | $0.007 / task | $0.177 / task lower (Claude Sonnet 5 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 Sonnet 5: 1.0% of Claude Max 5x (1.0% / 5h) 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 Sonnet 5 14610 good solves per month (Claude Sonnet 5 leads); per plan-dollar: 26.09 vs 146.10 (Claude Sonnet 5 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 Sonnet 5?
Claude Fable 5 clears higher: tier 4 of 5 versus tier 3 for Claude Sonnet 5 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 Sonnet 5?
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 Sonnet 5 used 2% of Claude Max 5x's weekly limit per pass, $0.024 per task at the listed price. Per task, Claude Sonnet 5 is about 7.0x cheaper ($0.024 vs $0.169).
Which gives more coding work per dollar, Claude Fable 5 or Claude Sonnet 5?
Claude Sonnet 5 delivers more benchmark work per subscription dollar: 12.18 suite runs per plan-dollar versus 2.21 for Claude Fable 5 (at $100/month priced 2026-07-20, 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 Sonnet 5 cost a month?
Claude Fable 5 runs on Claude Max 20x at $200/month (public price as of 2026-08-05). Claude Sonnet 5 runs on Claude Max 5x at $100/month (public price as of 2026-07-20).