Electricity Bench

Claude Sonnet 5.5

claude-code harness · Claude Max 5x ($100/mo)

Coding agent review, updated weekly (latest W40 2026).

Claude Sonnet 5.5 scores C- overall on Electricity Bench and clears tier 4 of 5 on real-world issues. Its best suite is spec planning at C+. One pass of our task set uses <1% of Claude Max 5x's weekly limit. In our own use it is our pick for high-volume work: the smallest problems.Measured

C-OVERALL

Clears tier 4 of 5 (partial at tier 5) on Real-world issues

Capability mean across 3 graded suite families.

capability
60%
plan cost per run
4.0% of Claude Max 5x
median task time
37s
reliability
100%
12345
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.

Clears level 3 of 5 (partial at levels 4 and 5) on Vibe coding v1 - the vaguest report level at which it still fixed every bug, having also cleared every richer level below
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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.

9 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

C-
Real-world issues v3
60%
plan cost per run
4.0% of Claude Max 5x
median task time
37s
reliability
100%
tier 1tier 2tier 3tier 4tier 5

12 of 15 tasks solved - grouped by tier, easiest first; hover a square for its time and turns.

Run on claude-code 2.1.284 (Claude Code), model claude-sonnet-5-5 (effort medium), week 2026-W40.

One run of this suite consumes 4.0% of Claude Max 5x.

Claude Max 5x's weekly limit holds about 13.8 fully spent 5h windows, out of the 33.6 a calendar week contains. Pooled over 402 runs in 15 session windows.

As work per window: about 3653 suite runs per month on this plan - 36.52 runs per plan-dollar (at $100/mo, priced 2026-07-20). 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/

C+
Spec planning v1
74%
plan cost per run
4.0% of Claude Max 5x
median task time
3m 25s
reliability
100%

0 of 4 tasks solved - hover a square for its time and turns.

Run on claude-code 2.1.284 (Claude Code), model claude-sonnet-5-5 (effort medium), week 2026-W40.

One run of this suite consumes 4.0% of Claude Max 5x.

Claude Max 5x's weekly limit holds about 13.8 fully spent 5h windows, out of the 33.6 a calendar week contains. Pooled over 402 runs in 15 session windows.

As work per window: about 3653 suite runs per month on this plan - 36.52 runs per plan-dollar (at $100/mo, priced 2026-07-20). 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/

D+
Vibe coding v1
48%
plan cost per solve
0.2% of Claude Max 5x
median task time
56s
reliability
100%
level 5level 4level 3level 2level 1issue aissue bissue cissue dissue e

19 of 25 tasks solved (9 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 2.1.284 (Claude Code), model claude-sonnet-5-5 (effort medium), week 2026-W40.

One good solve on this suite consumes 0.2% of Claude Max 5x on average.

Claude Max 5x's weekly limit holds about 13.8 fully spent 5h windows, out of the 33.6 a calendar week contains. Pooled over 402 runs in 15 session windows.

As work per window: about 73050 good solves per month on this plan - 730.50 solves per plan-dollar (at $100/mo, priced 2026-07-20). 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: 4.0% over 16 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 →

Suite
Real-world issues · 9 weeks graded · latest 2026-W40
20%30%40%50%60%70%2026-W322026-W342026-W362026-W382026-W40Claude Sonnet 5.5 · 2026-W32 · Aug 4, 2026 · 33% · FClaude Sonnet 5.5 · 2026-W33 · Aug 11, 2026 · 53% · D+Claude Sonnet 5.5 · 2026-W34 · Aug 18, 2026 · 50% · D+Claude Sonnet 5.5 · 2026-W35 · Aug 24, 2026 · 47% · DClaude Sonnet 5.5 · 2026-W36 · Aug 31, 2026 · 47% · DClaude Sonnet 5.5 · 2026-W37 · Sep 7, 2026 · 57% · C-Claude Sonnet 5.5 · 2026-W38 · Sep 14, 2026 · 58% · C-Claude Sonnet 5.5 · 2026-W39 · Sep 21, 2026 · 50% · D+Claude Sonnet 5.5 · 2026-W40 · Sep 28, 2026 · 53% · D+

Weekly heads

Newest week first. Click a row for usage.

WeekGradeCapabilityClearsTask timeUsage /1w
2026-W40 · v3D+53%tier 3 · p53m 35s1.0% of Claude Max 5x
2026-W39 · v3D+50%tier 2 · p52m 55s1.0% of Claude Max 5x
2026-W38 · v3C-58%tier 1 · p54m 17s2.0% of Claude Max 5x
2026-W37 · v3C-57%tier 2 · p53m 14s2.0% of Claude Max 5x
2026-W36 · v3D47%tier 4 · p53m 2s2.0% of Claude Max 5x
2026-W35 · v3D47%tier 4 · p52m 59s2.0% of Claude Max 5x
2026-W34 · v3D+50%tier 2 · p54m 22s2.0% of Claude Max 5x
2026-W33 · v3D+53%tier 3 · p55m 6s2.0% of Claude Max 5x
2026-W32 · v3F33%tier 3 · p53m 48s1.0% of Claude Max 5x

Embed this grade

Put Claude Sonnet 5.5's current grade in a README or a docs page.

Claude Sonnet 5.5 on Electricity Bench: C-

Markdown
[![Claude Sonnet 5.5 on Electricity Bench: C-](https://electricitybench.com/badge/claude-code-claude-sonnet-5-5.svg)](https://electricitybench.com/models/claude-code-claude-sonnet-5-5/)
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<a href="https://electricitybench.com/models/claude-code-claude-sonnet-5-5/"><img src="https://electricitybench.com/badge/claude-code-claude-sonnet-5-5.svg" alt="Claude Sonnet 5.5 on Electricity Bench: C-"></a>

Badges update every Monday with the weekly run. GitHub renders them from this URL.

Frequently asked questions

Is Claude Sonnet 5.5 worth it on Claude Max 5x?

On our private real-world suite (real-world@v3), Claude Sonnet 5.5 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 5x at $100/month (public price as of 2026-07-20). One full suite run consumed 4.0% of the plan's 5h window. Measured 2026-09-28.

Is Claude Sonnet 5.5 good for coding?

Claude Sonnet 5.5 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 2026-09-28.

How many coding tasks do you get with Claude Sonnet 5.5 on Claude Max 5x?

Roughly 3653 suite runs per month on Claude Max 5x, or 36.52 runs per plan-dollar at $100/month (priced 2026-07-20). 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 5x does one Claude Sonnet 5.5 task use?

One full suite run consumed 4.0% of Claude Max 5x'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 2026-09-28.

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