Electricity Bench

gpt-5.6-sol vs gpt-5.6-terra

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-solClears tier 4 (partial tier 5) at 3.5% of ChatGPT Plus per runCOVERALLgpt-5.6-terraClears tier 3 (partial tier 5) at 2.4% of ChatGPT Plus per runDOVERALL
real-world@v3CvsD
Dimensiongpt-5.6-solgpt-5.6-terraAdvantage
Capability60%53%+7% (gpt-5.6-sol leads)
Median task time2m 28s1m 49s40s faster (gpt-5.6-terra leads)
Approx. task cost$0.011 / task$0.007 / task$0.003 / task lower (gpt-5.6-terra leads)

gpt-5.6-sol: 3.5% of ChatGPT Plus (3.5% / 1w) per run. gpt-5.6-terra: 2.4% of ChatGPT Plus (2.4% / 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-solgpt-5.6-terraAdvantage
Capability67%62%+5% (gpt-5.6-sol leads)
Median task time4m 11s2m 15s1m 56s faster (gpt-5.6-terra leads)
Approx. task cost$0.010 / task$0.005 / task$0.005 / task lower (gpt-5.6-terra leads)

gpt-5.6-sol: 0.9% of ChatGPT Plus (0.9% / 1w) per run. gpt-5.6-terra: 0.4% of ChatGPT Plus (0.4% / 1w) per run. Each figure is a share of that agent's own plan, so there is no delta to draw.

vibe-coding@v1CvsD
Dimensiongpt-5.6-solgpt-5.6-terraAdvantage
Capability56%38%+18% (gpt-5.6-sol leads)
Median task time3m 43s2m 52s51s faster (gpt-5.6-terra leads)
Approx. task cost$0.011 / task$0.008 / task$0.003 / task lower (gpt-5.6-terra leads)

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

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

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

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