Electricity Bench

Claude Opus 5 vs Claude Opus 5.5

Claude Opus 5 was superseded by Claude Opus 5.5. 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 Opus 5.5 leads overall, B- to C. The two cost about the same per task. By suite, Claude Opus 5.5 takes real-world issues (C+ to C-) and spec planning (C+ to C). The data gives no reason to pick Claude Opus 5 over Claude Opus 5.5 this week.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 Opus 5.5 vs Claude Opus 5

Claude Opus 5.5 leads overall, B- to C. By suite: Claude Opus 5.5 takes real-world issues, C+ to C- (73% vs 57% capability); Claude Opus 5.5 takes spec planning, C+ to C (73% vs 66% capability); Claude Opus 5.5 takes vibe coding, B+ to C+ (90% vs 72% capability). Claude Opus 5 used 2% of Claude Max 5x's weekly limit per pass, $0.024 per task at the listed price. Claude Opus 5.5 used 2% of Claude Max 5x's weekly limit per pass, $0.024 per task at the listed price. Per task the two cost about the same ($0.024 vs $0.024). Claude Opus 5.5 is faster on real-world issues: a median task takes 1m 17s against 1m 56s. Both finished every task on it. The data gives no reason to pick Claude Opus 5 over Claude Opus 5.5 this week.

Changed since the previous graded week: Claude Opus 5: real-world issues usage 3% to 1% of the weekly limit; Claude Opus 5.5: real-world issues C- to C+, vibe coding B to B+.

Claude Opus 5Clears tier 2 (partial tier 5) at 21.0% of Claude Max 5x per runCOVERALLClaude Opus 5.5Clears tier 4 (partial tier 5) at 11.0% of Claude Max 5x per runB-OVERALL
real-world@v3C-vsC+
DimensionClaude Opus 5Claude Opus 5.5Advantage
Capability57%73%+17% (Claude Opus 5.5 leads)
Median task time1m 56s1m 17s39s faster (Claude Opus 5.5 leads)
Approx. task cost$0.015 / task$0.015 / taskEven

Claude Opus 5: 21.0% of Claude Max 5x (21.0% / 5h, 1.0% / 1w) per run. Its weekly limit holds about 13.8 of the week's 33.6 5h windows. Claude Opus 5.5: 11.0% of Claude Max 5x (11.0% / 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 Opus 5 696 vs Claude Opus 5.5 1328 suite runs per month (Claude Opus 5.5 leads); per plan-dollar: 6.96 vs 13.28 (Claude Opus 5.5 leads). Work figures compare outputs, so unlike quota shares they are comparable across plans.

spec-planning@v1CvsC+
DimensionClaude Opus 5Claude Opus 5.5Advantage
Capability66%73%+7% (Claude Opus 5.5 leads)
Median task time2m 9s4m 17s2m 8s faster (Claude Opus 5 leads)
Approx. task cost$0.057 / task$0.057 / taskEven

Claude Opus 5: 6.0% of Claude Max 5x (6.0% / 5h, 1.0% / 1w) per run. Its weekly limit holds about 13.8 of the week's 33.6 5h windows. Claude Opus 5.5: 6.0% of Claude Max 5x (6.0% / 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 Opus 5 2435 vs Claude Opus 5.5 2435 suite runs per month (Claude Opus 5 leads); per plan-dollar: 24.35 vs 24.35 (Claude Opus 5 leads). Work figures compare outputs, so unlike quota shares they are comparable across plans.

vibe-coding@v1C+vsB+
DimensionClaude Opus 5Claude Opus 5.5Advantage
Capability72%90%+18% (Claude Opus 5.5 leads)
Median task time2m 51s2m 44s7s faster (Claude Opus 5.5 leads)
Approx. task cost$0.011 / task$0.007 / task$0.004 / task lower (Claude Opus 5.5 leads)

Claude Opus 5: 1.6% of Claude Max 5x (1.6% / 5h) per good solve. Its weekly limit holds about 13.8 of the week's 33.6 5h windows. Claude Opus 5.5: 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 Opus 5 9131 vs Claude Opus 5.5 14610 good solves per month (Claude Opus 5.5 leads); per plan-dollar: 91.31 vs 146.10 (Claude Opus 5.5 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 Opus 5 or Claude Opus 5.5?

Claude Opus 5.5 clears higher: tier 4 of 5 versus tier 2 for Claude Opus 5 on real-world@v3, our private suite of real-world coding problems. Latest measurement 2026-09-21.

Which is cheaper per task, Claude Opus 5 or Claude Opus 5.5?

Claude Opus 5 used 2% of Claude Max 5x's weekly limit per pass, $0.024 per task at the listed price. Claude Opus 5.5 used 2% of Claude Max 5x's weekly limit per pass, $0.024 per task at the listed price. Per task the two cost about the same ($0.024 vs $0.024).

Which gives more coding work per dollar, Claude Opus 5 or Claude Opus 5.5?

Claude Opus 5.5 delivers more benchmark work per subscription dollar: 13.28 suite runs per plan-dollar versus 6.96 for Claude Opus 5 (at $100/month priced 2026-07-27, and $100/month priced 2026-07-27). Work figures compare outputs, so unlike raw quota shares they are comparable across plans.

What do Claude Opus 5 and Claude Opus 5.5 cost a month?

Claude Opus 5 runs on Claude Max 5x at $100/month (public price as of 2026-07-27). Claude Opus 5.5 runs on Claude Max 5x at $100/month (public price as of 2026-07-27).