Pyyan / Compare / Claude Mythos 5 vs GPT-6 Astra

Claude Mythos 5 vs GPT-6 Astra

2 of 5

Language Models · verified 5 Sept 2026

Claude Mythos 5Anthropicpreview
GPT-6 AstraOpenAIcurrent
3 slots left
SpecificationClaude Mythos 5GPT-6 Astra
SummaryFable 5's capabilities via Project Glasswing.Saturates three of the benchmarks it reports, and ships disabled for enterprise.
Context1M1.05M
Input ($/Mtok)$10$10
Output ($/Mtok)$50$50
LicenceProprietaryProprietary
Max output128K128K
Parameters—Not published
Released—3 Sep 2026
Model IDclaude-mythos-5gpt-6-astra
CategoryLanguage ModelsLanguage Models
OfficialAnthropic ↗—

Highlighted rows are where these differ.

Claude Mythos 5

  • Same capabilities, pricing and API surface as Fable 5
  • Access only through Project Glasswing

Best for Glasswing participants.

Full spec sheet →

GPT-6 Astra

  • 97.6% on FrontierMath Tier 4, 99.9% on ARC-AGI-3 and 100% on ExploitBench
  • Above 272K input tokens the whole request reprices: input and cache at 2x, output at 1.5x
  • Rolls out to OpenAI's Daybreak cyber programme first, and arrives switched off for enterprise

Best for hard reasoning and computer use.

Full spec sheet →