Claude Mythos Preview vs GPT-5.3 Codex
Rank, tier, score and price side by side, from our weekly rankings. Scores are editorial opinion based on public sources.
A
Claude Mythos Preview
B
GPT-5.3 Codex
- ProviderAnthropicOpenAI
- Rank#33#31Higher rank
- TierAA
- Score82.482.9Higher score
- PriceInvite-only via Project Glasswing; $25 input / $125 output per 1M tokens after creditsAPI $1.75 input / $14 output per 1M tokensLower price tier
- TaglineAnthropic's invite-only cybersecurity research preview offered through Project Glasswing, deprecated on the Claude API since June 2026.OpenAI's February 2026 agentic coding model combining code generation with general-purpose intelligence, since folded into GPT-5.4 and followed by the GPT-5.5 and GPT-5.6 families.
| Attribute | Claude Mythos Preview | GPT-5.3 Codex |
|---|---|---|
| Provider | Anthropic | OpenAI |
| Rank | #33 | #31Higher rank |
| Tier | A | A |
| Score | 82.4 | 82.9Higher score |
| Price | Invite-only via Project Glasswing; $25 input / $125 output per 1M tokens after credits | API $1.75 input / $14 output per 1M tokensLower price tier |
| Tagline | Anthropic's invite-only cybersecurity research preview offered through Project Glasswing, deprecated on the Claude API since June 2026. | OpenAI's February 2026 agentic coding model combining code generation with general-purpose intelligence, since folded into GPT-5.4 and followed by the GPT-5.5 and GPT-5.6 families. |