Head-to-Head Model Showdown
Claude vs ChatGPT (Opus 5.5 vs GPT-6 Astra)
Claude Opus 5.5 vs GPT-6 Astra side by side: arena.ai text score, list price per 1M tokens, context window and licence, with sources. Data checked 2026-10-11.
Executive Verdict
On the arena.ai text leaderboard, Claude Opus 5.5 scores 1507 (±8, #2) and GPT-6 Astra scores 1475 (±7, #35). Claude Opus 5.5 leads by 32 points, outside the margin of error. Claude Opus 5.5: $4.00 input / $20.00 output per 1M tokens. GPT-6 Astra: $10.00 / $50.00. Blended at 3 input : 1 output, Claude Opus 5.5 costs 60% less ($8.00 vs $20.00 per 1M tokens). Context windows are about the same: Claude Opus 5.5 1M tokens, GPT-6 Astra 1.05M tokens. Both are proprietary and available only as hosted APIs.