Electricity Bench

Claude Opus 5.5 vs Composer 2.5

Claude Opus 5.5 leads overall, B- to D. 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 D). The data gives no reason to pick Composer 2.5 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: Composer 2.5 vs Claude Opus 5.5

Claude Opus 5.5 leads overall, B- to D. 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 D (73% vs 48% capability); Claude Opus 5.5 takes vibe coding, B+ to F (90% vs 23% capability). Claude Opus 5.5 used 2% of Claude Max 5x's weekly limit per pass, $0.024 per task at the listed price. Composer 2.5 used 2.0% of Cursor Pro's monthly limit per pass, $0.021 per task at the listed price. Per task the two cost about the same ($0.024 vs $0.021). Claude Opus 5.5 is faster on real-world issues: a median task takes 1m 17s against 1m 34s. Both finished every task on it. The data gives no reason to pick Composer 2.5 over Claude Opus 5.5 this week.

Changed since W39: Claude Opus 5.5: real-world issues C- to C+, vibe coding B to B+; Composer 2.5: real-world issues D+ to C-.

Claude Opus 5.5Clears tier 4 (partial tier 5) at 11.0% of Claude Max 5x per runB-OVERALLComposer 2.5Clears tier 1 (partial tier 5) at 1.6% of Cursor Pro per runDOVERALL
real-world@v3C+vsC-
DimensionClaude Opus 5.5Composer 2.5Advantage
Capability73%57%+17% (Claude Opus 5.5 leads)
Median task time1m 17s1m 34s18s faster (Claude Opus 5.5 leads)
Approx. task cost$0.015 / task$0.021 / task$0.006 / task lower (Claude Opus 5.5 leads)

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. Composer 2.5: 1.6% of Cursor Pro (1.6% / 1m) per run. Each figure is a share of that agent's own plan, so there is no delta to draw.

Work per window: Claude Opus 5.5 1328 vs Composer 2.5 63 suite runs per month (Claude Opus 5.5 leads); per plan-dollar: 13.28 vs 3.15 (Claude Opus 5.5 leads). Work figures compare outputs, so unlike quota shares they are comparable across plans.

spec-planning@v1C+vsD
DimensionClaude Opus 5.5Composer 2.5Advantage
Capability73%48%+25% (Claude Opus 5.5 leads)
Median task time4m 17s1m 8s3m 9s faster (Composer 2.5 leads)
Approx. task cost$0.057 / task$0.022 / task$0.035 / task lower (Composer 2.5 leads)

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. Composer 2.5: 0.4% of Cursor Pro (0.4% / 1m) per run. Each figure is a share of that agent's own plan, so there is no delta to draw.

Work per window: Claude Opus 5.5 2435 vs Composer 2.5 225 suite runs per month (Claude Opus 5.5 leads); per plan-dollar: 24.35 vs 11.23 (Claude Opus 5.5 leads). Work figures compare outputs, so unlike quota shares they are comparable across plans.

vibe-coding@v1B+vsF
DimensionClaude Opus 5.5Composer 2.5Advantage
Capability90%23%+67% (Claude Opus 5.5 leads)
Median task time2m 44s1m 37s1m 8s faster (Composer 2.5 leads)
Approx. task cost$0.007 / task$0.022 / task$0.015 / task lower (Claude Opus 5.5 leads)

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. Composer 2.5: 0.1% of Cursor Pro (0.1% / 1m) per good solve. Each figure is a share of that agent's own plan, so there is no delta to draw.

Work per window: Claude Opus 5.5 14610 vs Composer 2.5 920 good solves per month (Claude Opus 5.5 leads); per plan-dollar: 146.10 vs 46.02 (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 5.5 or Composer 2.5?

Claude Opus 5.5 clears higher: tier 4 of 5 versus tier 1 for Composer 2.5 on real-world@v3, our private suite of real-world coding problems. Latest measurement 2026-09-28.

Which is cheaper per task, Claude Opus 5.5 or Composer 2.5?

Claude Opus 5.5 used 2% of Claude Max 5x's weekly limit per pass, $0.024 per task at the listed price. Composer 2.5 used 2.0% of Cursor Pro's monthly limit per pass, $0.021 per task at the listed price. Per task the two cost about the same ($0.024 vs $0.021).

Which gives more coding work per dollar, Claude Opus 5.5 or Composer 2.5?

Claude Opus 5.5 delivers more benchmark work per subscription dollar: 13.28 suite runs per plan-dollar versus 3.15 for Composer 2.5 (at $100/month priced 2026-07-27, and $20/month priced 2026-07-20). Work figures compare outputs, so unlike raw quota shares they are comparable across plans.

What do Claude Opus 5.5 and Composer 2.5 cost a month?

Claude Opus 5.5 runs on Claude Max 5x at $100/month (public price as of 2026-07-27). Composer 2.5 runs on Cursor Pro at $20/month (public price as of 2026-07-20).