Electricity Bench

Claude Opus 5.5 vs GPT-6 Sol

GPT-6 Sol was superseded by GPT-6.1 Sol. 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-. GPT-6 Sol is about 1.4x cheaper per task. By suite, Claude Opus 5.5 takes real-world issues (C+ to C-) and spec planning (C+ to C-). Take GPT-6 Sol 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: GPT-6 Sol vs Claude Opus 5.5

Claude Opus 5.5 leads overall, B- to C-. By suite: Claude Opus 5.5 takes real-world issues, C+ to C- (73% vs 55% capability); Claude Opus 5.5 takes spec planning, C+ to C- (73% vs 60% capability); Claude Opus 5.5 takes vibe coding, B+ to C- (90% vs 61% capability). Claude Opus 5.5 used 2% of Claude Max 5x's weekly limit per pass, $0.024 per task at the listed price. GPT-6 Sol used 7% of ChatGPT Plus's weekly limit per pass, $0.017 per task at the listed price; at the ~$100 tier the board defaults to that is an estimated ~1.4% of ChatGPT Pro 5x's weekly limit (est, about $0.017 per task). Per task, GPT-6 Sol is about 1.4x cheaper ($0.017 vs $0.024). Claude Opus 5.5 is faster on real-world issues: a median task takes 1m 17s against 1m 41s. Both finished every task on it. Reasons to pick GPT-6 Sol anyway: it is cheaper per task ($0.017 vs $0.024).

Changed since W39: Claude Opus 5.5: real-world issues C- to C+, vibe coding B to B+; GPT-6 Sol: real-world issues D- to C-, real-world issues usage 4% to 5% of the weekly limit, spec planning C to C-, spec planning usage 1% to 2% of the weekly limit, vibe coding D+ to C-.

Claude Opus 5.5Clears tier 4 (partial tier 5) at 11.0% of Claude Max 5x per runB-OVERALLGPT-6 SolClears tier 1 (partial tier 5) at 5.0% of ChatGPT Plus per runC-OVERALL
real-world@v3C+vsC-
DimensionClaude Opus 5.5GPT-6 SolAdvantage
Capability73%55%+18% (Claude Opus 5.5 leads)
Median task time1m 17s1m 41s25s faster (Claude Opus 5.5 leads)
Approx. task cost$0.015 / task$0.015 / taskEven

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. GPT-6 Sol: 5.0% of ChatGPT Plus (35.0% / 5h, 5.0% / 1w) per run. Its weekly limit holds about 6 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.

spec-planning@v1C+vsC-
DimensionClaude Opus 5.5GPT-6 SolAdvantage
Capability73%60%+12% (Claude Opus 5.5 leads)
Median task time4m 17s2m 58s1m 19s faster (GPT-6 Sol leads)
Approx. task cost$0.057 / task$0.023 / task$0.034 / task lower (GPT-6 Sol 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. GPT-6 Sol: 2.0% of ChatGPT Plus (10.0% / 5h, 2.0% / 1w) per run. Its weekly limit holds about 6 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.

vibe-coding@v1B+vsC-
DimensionClaude Opus 5.5GPT-6 SolAdvantage
Capability90%61%+28% (Claude Opus 5.5 leads)
Median task time2m 44s2m 44s0s faster (GPT-6 Sol leads)
Approx. task cost$0.007 / task$0.018 / task$0.012 / 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. GPT-6 Sol: 0.4% of ChatGPT Plus (1.8% / 5h, 0.4% / 1w) per good solve. Its weekly limit holds about 6 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.

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 GPT-6 Sol?

Claude Opus 5.5 clears higher: tier 4 of 5 versus tier 1 for GPT-6 Sol 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 GPT-6 Sol?

Claude Opus 5.5 used 2% of Claude Max 5x's weekly limit per pass, $0.024 per task at the listed price. GPT-6 Sol used 7% of ChatGPT Plus's weekly limit per pass, $0.017 per task at the listed price; at the ~$100 tier the board defaults to that is an estimated ~1.4% of ChatGPT Pro 5x's weekly limit (est, about $0.017 per task). Per task, GPT-6 Sol is about 1.4x cheaper ($0.017 vs $0.024).

What do Claude Opus 5.5 and GPT-6 Sol cost a month?

Claude Opus 5.5 runs on Claude Max 5x at $100/month (public price as of 2026-07-27). GPT-6 Sol runs on ChatGPT Plus at $20/month (public price as of 2026-07-20).