Electricity Bench

GPT-6 Astra vs Composer 2.5

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-6 AstraClears tier 2 (partial tier 5) at 3.0% of ChatGPT Pro $100 per runCOVERALLComposer 2.5Clears tier 2 (partial tier 5) at 1.8% of Cursor Pro per runDOVERALL
real-world@v3CvsC
DimensionGPT-6 AstraComposer 2.5Advantage
Capability57%57%Even
Median task time1m 56s1m 49s8s faster (Composer 2.5 leads)
Approx. task cost$0.046 / task$0.024 / task$0.022 / task lower (Composer 2.5 leads)

GPT-6 Astra: 3.0% of ChatGPT Pro $100 (3.0% / 1w) per run. Composer 2.5: 1.8% of Cursor Pro (1.8% / 1m) per run. Each figure is a share of that agent's own plan, so there is no delta to draw.

spec-planning@v1CvsD
DimensionGPT-6 AstraComposer 2.5Advantage
Capability74%49%+25% (GPT-6 Astra leads)
Median task time4m 0s1m 49s2m 11s faster (Composer 2.5 leads)
Approx. task cost$0.057 / task$0.023 / task$0.035 / task lower (Composer 2.5 leads)

GPT-6 Astra: 1.0% of ChatGPT Pro $100 (1.0% / 1w) per run. Composer 2.5: 0.5% of Cursor Pro (0.5% / 1m) per run. Each figure is a share of that agent's own plan, so there is no delta to draw.

vibe-coding@v1CvsF
DimensionGPT-6 AstraComposer 2.5Advantage
Capability61%35%+26% (GPT-6 Astra leads)
Median task time2m 54s2m 13s41s faster (Composer 2.5 leads)
Approx. task cost$0.046 / task$0.028 / task$0.018 / task lower (Composer 2.5 leads)

GPT-6 Astra: 0.2% of ChatGPT Pro $100 (0.2% / 1w) per good solve. 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.

Grades and deltas are comparable only within a suite version. See methodology.

Frequently asked questions

Which is better for coding, GPT-6 Astra or Composer 2.5?

They are even on our ladder: both clear tier 2 of 5 at 57% capability on real-world@v3, our private suite of real-world coding problems. Latest measurement 2026-09-05.

How much do GPT-6 Astra and Composer 2.5 cost?

GPT-6 Astra runs on ChatGPT Pro $100 at $100/month (public price as of 2026-09-05). Composer 2.5 runs on Cursor Pro at $20/month (public price as of 2026-07-20).