GPT-5.3 Codex vs Claude Mythos Preview
Rank, tier, score and price side by side, from our weekly rankings. Scores are editorial opinion based on public sources.
A
GPT-5.3 Codex
B
Claude Mythos Preview
- ProviderOpenAIAnthropic
- Rank#31Higher rank#33
- TierAA
- Score82.9Higher score82.4
- PriceAPI $1.75 input / $14 output per 1M tokensLower price tierInvite-only via Project Glasswing; $25 input / $125 output per 1M tokens after credits
- TaglineOpenAI'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.Anthropic's invite-only cybersecurity research preview offered through Project Glasswing, deprecated on the Claude API since June 2026.
| Attribute | GPT-5.3 Codex | Claude Mythos Preview |
|---|---|---|
| Provider | OpenAI | Anthropic |
| Rank | #31Higher rank | #33 |
| Tier | A | A |
| Score | 82.9Higher score | 82.4 |
| Price | API $1.75 input / $14 output per 1M tokensLower price tier | Invite-only via Project Glasswing; $25 input / $125 output per 1M tokens after credits |
| Tagline | 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. | Anthropic's invite-only cybersecurity research preview offered through Project Glasswing, deprecated on the Claude API since June 2026. |