Electricity Bench

gpt-5.6-luna vs gpt-5.6-sol

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.

gpt-5.6-lunaClears tier 3 (partial tier 5) at 2.9% of ChatGPT Plus per runDOVERALLgpt-5.6-solClears tier 4 (partial tier 5) at 3.5% of ChatGPT Plus per runCOVERALL
real-world@v3DvsC
Dimensiongpt-5.6-lunagpt-5.6-solAdvantage
Capability53%60%+7% (gpt-5.6-sol leads)
Median task time1m 59s2m 28s30s faster (gpt-5.6-luna leads)
Approx. task cost$0.009 / task$0.011 / task$0.002 / task lower (gpt-5.6-luna leads)

gpt-5.6-luna: 2.9% of ChatGPT Plus (2.9% / 1w) per run. gpt-5.6-sol: 3.5% of ChatGPT Plus (3.5% / 1w) per run. Each figure is a share of that agent's own plan, so there is no delta to draw.

spec-planning@v1CvsC
Dimensiongpt-5.6-lunagpt-5.6-solAdvantage
Capability58%67%+9% (gpt-5.6-sol leads)
Median task time2m 11s4m 11s2m 0s faster (gpt-5.6-luna leads)
Approx. task cost$0.004 / task$0.010 / task$0.006 / task lower (gpt-5.6-luna leads)

gpt-5.6-luna: 0.3% of ChatGPT Plus (0.3% / 1w) per run. gpt-5.6-sol: 0.9% of ChatGPT Plus (0.9% / 1w) per run. Each figure is a share of that agent's own plan, so there is no delta to draw.

vibe-coding@v1FvsC
Dimensiongpt-5.6-lunagpt-5.6-solAdvantage
Capability28%56%+28% (gpt-5.6-sol leads)
Median task time2m 44s3m 43s1m 0s faster (gpt-5.6-luna leads)
Approx. task cost$0.008 / task$0.011 / task$0.004 / task lower (gpt-5.6-luna leads)

gpt-5.6-luna: 0.2% of ChatGPT Plus (0.2% / 1w) per good solve. gpt-5.6-sol: 0.2% of ChatGPT Plus (0.2% / 1w) per good solve. 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, gpt-5.6-luna or gpt-5.6-sol?

gpt-5.6-sol clears higher: tier 4 of 5 versus tier 3 for gpt-5.6-luna on real-world@v3, our private suite of real-world coding problems. Latest measurement 2026-08-17.

How much do gpt-5.6-luna and gpt-5.6-sol cost?

gpt-5.6-luna runs on ChatGPT Plus at $20/month (public price as of 2026-07-20). gpt-5.6-sol runs on ChatGPT Plus at $20/month (public price as of 2026-07-20).