The Model Index
Up to four models

Compare

Side by side on the same independent tests, with price and context. The link in your address bar shares this exact comparison.

GPT-6.1 SolGPT-5.6 Terra
Next to GPT-6.1 Sol
Presets
GPT-6.1 Sol
184168–200
WeightsClosed
ReleasedSep 2026
Price in / out$2.0 / $10
Context1.05M
Core tests taken3 of 8
GPT-5.6 Terra
178167–189
WeightsClosed
ReleasedJul 2026
Price in / out$2.0 / $12
Context1.05M
Core tests taken4 of 8

GPT-6.1 Sol and GPT-5.6 Terra are too close to call (6 points apart, within the uncertainty), ahead on 3 of 3 shared core tests, at a similar price.

Test by testindependent results · Epoch AI

GPT-6.1 SolGPT-5.6 Terra

Only tests that at least two of these models have taken. Bold rows are the core tests shown on every profile; all of these results inform the index score. Task length (METR) is listed below the chart because it is a duration, not a percentage.