Claude Fable 5.2 vs GPT-6 Astra

As of November 9, 2026, Claude Fable 5.2 costs $8.00 input and $40.00 output per 1M tokens, and GPT-6 Astra costs $10.00 and $50.00. Claude Fable 5.2 is the cheaper of the two.

Two months after GPT-6 Astra and Claude Fable 5.1 landed on the identical $10/$50 list, Anthropic broke the tie. Claude Fable 5.2, released November 9, 2026, lists $8 per million input tokens and $40 output, 20 percent under Astra on both sides, and its cache reads cost $0.20 per million against $1 for Astra cached input. Astra still bills any request above 272,000 input tokens at 2x input and cache rates and 1.5x output, which puts its long-context tier at $20 and $75, while Fable 5.2 carries one rate across its full 1 million token window with 128K output. Astra's window is nominally larger at 1,050,000 tokens. On Anthropic's launch table, which is vendor-run for both columns, Fable 5.2 scores 49.1 percent on FrontierCode 2.0 at xhigh effort against 42.8 for Astra, and the first independent read points the same way: Vals AI puts Fable 5.2 first of 36 models on its Vals Index at 71.31 percent as of November 9, 2026. Astra's published strengths sit on rows where we carry no Fable 5.2 figure: OpenAI reports 96.0 on GPQA Diamond, 91.5 on BrowseComp, and 96.3 percent on MRCR v2 8-needle between 512K and 1M tokens. Speed is its own line item on the Anthropic side, since Fable 5.2 output runs up to 30 percent faster than Fable 5.1 and a fast mode at $16 and $80 generates up to 2.5x faster. Anthropic also reports about 55 percent fewer safety classifier blocks than Fable 5.1, which matters for security-adjacent work, and organizations that need lighter cyber and biology safeguards can apply for Mythos 5.2, the same model behind a verification gate at the same price.