Claude Fable 5
claude-code harness · Claude Max 20x ($200/mo)
Coding agent review, updated weekly (latest W40 2026).
Claude Fable 5 scores C overall on Electricity Bench and clears tier 4 of 5 on real-world issues. Its best suite is vibe coding at C+. One pass of our task set uses 7% of Claude Max 20x's weekly limit.Measured
No longer on the leaderboard. These grades stay published as the record of what this agent scored while it ran.
Clears tier 4 of 5 (partial at tier 5) on Real-world issues
Capability mean across 3 graded suite families.
What the tiers mean
"Clears" marks the highest rung where every task at it and below was solved. Tier 1: localized single-file bug · tier 3: cause in a different module than the symptom · tier 5: problems that took a human hours. A cleared rung solved every task on it; a partial rung solved some. The headline stops at the last unbroken rung, so a solved tier above a half-solved one counts only as partial.
What the levels mean
Level 1: a full brief naming the surface and the acceptance · level 3: the report as filed · level 5: a vague vibe report in a non-technical user's words. Context falls as the level rises, so vaguer is harder. A cleared level fixed every bug at it and below; a partial level fixed some. The headline stops at the last unbroken level, so a fix above a half-cleared level counts only as partial.
10 of this suite's tasks were credited rather than run: on a suite that asks the same problem at several levels of detail, solving it from the vaguest description credits the more detailed ones instead of asking again.
Per-suite results
12 of 15 tasks solved - grouped by tier, easiest first; hover a square for its time and turns.
Run on claude-code 2.1.251 (Claude Code), model claude-fable-5 (effort medium), week 2026-W36.
One run of this suite consumes 33.0% of Claude Max 20x's 5h window and 5.0% of the weekly limit.
Claude Max 20x's weekly limit holds about 7 fully spent 5h windows, out of the 33.6 a calendar week contains. Pooled over 912 runs in 31 session windows.
As work per window: about 443 suite runs per month on this plan - 2.21 runs per plan-dollar (at $200/mo, priced 2026-08-05). Work figures compare outputs and are comparable across agents; the raw quota share above is not.
How the plan cost was measured
Measured per suite run (reported-delta); an absolute cost on this plan, not comparable with another agent's plan. Measured on a shared personal subscription during a quiet window, not a dedicated bench login.
How the limits work on Claude Code: /limits/claude-code/
0 of 4 tasks solved - hover a square for its time and turns.
Run on claude-code 2.1.251 (Claude Code), model claude-fable-5 (effort medium), week 2026-W36.
One run of this suite consumes 10.0% of Claude Max 20x's 5h window and 2.0% of the weekly limit.
Claude Max 20x's weekly limit holds about 7 fully spent 5h windows, out of the 33.6 a calendar week contains. Pooled over 912 runs in 31 session windows.
As work per window: about 1461 suite runs per month on this plan - 7.30 runs per plan-dollar (at $200/mo, priced 2026-08-05). Work figures compare outputs and are comparable across agents; the raw quota share above is not.
How the plan cost was measured
Measured per suite run (reported-delta); an absolute cost on this plan, not comparable with another agent's plan. Measured on a shared personal subscription during a quiet window, not a dedicated bench login.
How the limits work on Claude Code: /limits/claude-code/
22 of 25 tasks solved (10 credited without running) - each row is one bug, vaguest report first and context growing to the right; hover a square for its time and turns.
Run on claude-code 2.1.251 (Claude Code), model claude-fable-5 (effort medium), week 2026-W36.
One good solve on this suite consumes, on average, 2.8% of Claude Max 20x's 5h window and 0.4% of the weekly limit.
Claude Max 20x's weekly limit holds about 7 fully spent 5h windows, out of the 33.6 a calendar week contains. Pooled over 912 runs in 31 session windows.
As work per window: about 5218 good solves per month on this plan - 26.09 solves per plan-dollar (at $200/mo, priced 2026-08-05). Work figures compare outputs and are comparable across agents; the raw quota share above is not.
How the plan cost was measured
Counted over each issue's first solve (5 solves); the walk's failed harder cells and confirmation runs are the benchmark's own search cost and are excluded (full walk: 42.0% over 15 cells). Measured per cell run (reported-delta); an absolute cost on this plan, not comparable with another agent's plan. Measured on a shared personal subscription during a quiet window, not a dedicated bench login.
How the limits work on Claude Code: /limits/claude-code/
Task outputs from these runs are withheld: publishing them would reveal the private suite. Per-task scores, times and turns are in the chips above.
Trajectory
One point per grading week - a re-run within a week shows only its latest execution. Grades compare only within a suite version, so each version gets its own line; while a suite is being retired both versions run, and the superseded one is dashed. The filled point is the run the scorecard shows today. Click a point or week for plan usage. All agents over time →
Weekly heads
Newest week first. Click a row for usage.
| Week | Grade | Capability | Usage /1w |
|---|---|---|---|
| 2026-W36 · v3now | C- | 60% | 33.0% |
| 2026-W35 · v3 | C+ | 73% | 32.0% |
| 2026-W34 · v3 | C- | 60% | 34.0% |
| 2026-W33 · v3 | C- | 60% | 34.0% |
| 2026-W32 · v3 | C- | 60% | 30.5% |
Embed this grade
Put Claude Fable 5's current grade in a README or a docs page.
[](https://electricitybench.com/models/claude-code-claude-fable-5/)<a href="https://electricitybench.com/models/claude-code-claude-fable-5/"><img src="https://electricitybench.com/badge/claude-code-claude-fable-5.svg" alt="Claude Fable 5 on Electricity Bench: C"></a>Badges update every Monday with the weekly run. GitHub renders them from this URL.
Frequently asked questions
Is Claude Fable 5 worth it on Claude Max 20x?
On our private real-world suite (real-world@v3), Claude Fable 5 earned grade C- with 60% capability, clearing every problem up to tier 4 of 5 - a cross-cutting problem needing broad codebase orientation and landing some tier 5 problems. It runs on Claude Max 20x at $200/month (public price as of 2026-08-05). One full suite run consumed 33.0% of the plan's 5h window. Measured 2026-08-30.
Is Claude Fable 5 good for coding?
Claude Fable 5 clears tier 4 of our five-tier real-world ladder - every task at that tier and below - where tier 1 is a localized single-file bug and tier 5 is a problem that took a human engineer hours. It solves some but not all tasks up at tier 5. Its capability score on real-world@v3 is 60% (grade C-). Last benchmarked 2026-08-30.
How many coding tasks do you get with Claude Fable 5 on Claude Max 20x?
Roughly 443 suite runs per month on Claude Max 20x, or 2.21 runs per plan-dollar at $200/month (priced 2026-08-05). Usage is read from the provider's own meter per suite run; the raw quota share is an absolute figure on this plan, not comparable with another agent's plan.
How much of Claude Max 20x does one Claude Fable 5 task use?
One full suite run consumed 33.0% of Claude Max 20x's 5h limit, read off the provider's own meter before and after the run. A benchmark task is a whole multi-turn agent session, not a message, and the share belongs to this plan alone: it is not comparable with another agent's plan. Measured 2026-08-30.
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