Up to four models

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

GPT-6 AstraClaude Sonnet 5.5

Next to GPT-6 Astra

Presets

GPT-6 Astra

197186–209

WeightsClosed

ReleasedSep 2026

Price in / out$10 / $50

Context1.05M

Core tests taken5 of 8

Claude Sonnet 5.5

193182–205

WeightsClosed

ReleasedSep 2026

Price in / out$2.0 / $10

Context1M

Core tests taken3 of 8

GPT-6 Astra and Claude Sonnet 5.5 are too close to call (4 points apart, within the uncertainty), ahead on 2 of 3 shared core tests, at 5.0× the price.

Test by testindependent results · Epoch AI

GPT-6 AstraClaude Sonnet 5.5

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.