Compare · AI models
GPT-5.5 Pro vs GPT-5.6 Sol
RANKED BY EPOCH CAPABILITIES INDEX (ECI)
#5 VS #6
CHECKED 28 SEPT 2026
Side by side
Verdict
GPT-5.5 Pro ranks #5 of 20 on Epoch Capabilities Index (ECI) (162.45); GPT-5.6 Sol ranks #6 (161.99).
Rank 05 of 20 · leads
Epoch Capabilities Index (ECI)
162.45
MakerOpenAI
Date2026
Verified—
Evidence
Epoch AI epoch_capabilities_index/eci_scores.csv (LLM Benchmark Data ZIP, fetched 2026-09-28). ECI 162.45, accessibility API access, release date 2026-04-23. Pricing/context via Statlyte (statlyte.com/models/openai/gpt-5-5-pro), MIT licensed.Rank 06 of 20
Epoch Capabilities Index (ECI)
161.99
MakerOpenAI
Date2026
Verified—
Evidence
Epoch AI epoch_capabilities_index/eci_scores.csv (LLM Benchmark Data ZIP, fetched 2026-09-28). ECI 161.99, accessibility API access, release date 2026-07-09. Pricing/context via Statlyte (statlyte.com/models/openai/gpt-5-6-sol), MIT licensed.Try another pair
More GPT-5.5 Pro matchups
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- GPT-5.5 Pro vs Claude Fable 5.1
- GPT-5.5 Pro vs Claude Fable 5
- GPT-5.5 Pro vs Claude Opus 5
- GPT-5.5 Pro vs GPT-5.6 Terra
- GPT-5.5 Pro vs GPT-5.5
- GPT-5.5 Pro vs GPT-5.4 Pro
- GPT-5.5 Pro vs Claude Opus 4.8
- GPT-5.5 Pro vs Gemini 3.7 Flash
- GPT-5.5 Pro vs Kimi K3
- GPT-5.5 Pro vs Gemini 3.8 Flash
- GPT-5.5 Pro vs GPT-5.4
Source Ranking: Epoch AI, AI Benchmarking Hub, Epoch Capabilities Index (epoch.ai/data/benchmark_data.zip, CC BY 4.0). Per-entry pricing/context:…
Last checked 28 Sept 2026