LOADING DATASHEET
GROUNDED IN REAL HUMAN CONVERSATIONSYOUR BENCH
Claude Mythos Preview
by Anthropic
CLOSEDHOSTEDAPIPAIDLONG CONTEXT
RANKED #194 OF 230 ASSISTANTS · OVERALL #299 OF 6,608 · VIBE SCORE 5.4 · 52 VOICES
Claude Mythos Preview available through cloud APIs.
HAPPY7.6
15 mentions
SAD7.4
5 mentions
VIBE TRAJECTORY
26 weeks · 94 voices
QUIETLY DEGRADING
Recent vibe and chatter are both sliding.
HOW TO USE IT
Closed model. Anthropic hosts it, so you use it through an app or an API.
PREFER OPEN SOURCE? THE CROWD HAS PICKS
Claude Mythos Preview is closed, so you rent it. These open-weight models can genuinely stand in for it. Download once, own forever.
- OPEN WEIGHTS6.5
DeepSeek V4 ProDeepSeekChoose for top-tier open weights with near-frontier reasoning and coding.🏆 NEAR-PEER QUALITY💻 STRONG AT CODE💸 COST EFFICIENT3.4k VOICESMATCH★★★ - OPEN WEIGHTS7.4DeepSeek V4 FlashDeepSeekChoose when you need rapid responses, high agentic coding power, and low cost.⚡ FAST💸 COST EFFICIENT💻 STRONG AT CODE5.0k VOICESMATCH★★★
- OPEN WEIGHTS6.4
Kimi K2MoonshotChoose for versatile general-purpose text, strong writing, and tool use.🏆 NEAR-PEER QUALITY💻 STRONG AT CODE💸 COST EFFICIENT353 VOICESMATCH★★★
WHAT THE INTERNET SAYS
Not enough discussion about Claude Mythos Preview yet to call it. We found 52 posts but people did not say much either way.
42 POSTS · 10 COMMENTS · BLUESKY · X · DEV.TO · LEMMY · REDDIT · HACKER NEWS · BLOG · GITHUB
PEOPLE LOVE
- No fan mail yet. The crowd is still warming up.
PEOPLE COMPLAIN ABOUT
- No complaints yet. The internet is still looking for one. Suspicious.
LOOKING FOR AN ALTERNATIVE?
Other models the crowd has fully reviewed, starting with text models like this one.
GLM 5.3> SOURCES (12)
- REDDIT · 2026-05-07 · 1362 UPVOTESFirefox reports a massive April spike in security fixes after using Claude Mythos for bug hunting
Firefox reports a massive April spike in security fixes after using Claude Mythos for bug hunting
- REDDIT · 2026-04-07 · 787 UPVOTESThe 244-page System Card for Claude Mythos Preview is terrifying
The 244-page System Card for Claude Mythos Preview is terrifying
- REDDIT · 2026-04-07 · 533 UPVOTESClaude Mythos Preview Benchmarks
Claude Mythos Preview Benchmarks
- REDDIT · 2026-05-09 · 485 UPVOTESMETR evaluated an early version of Claude Mythos
METR evaluated an early version of Claude Mythos
- REDDIT · 2026-05-16 · 393 UPVOTESClaude Mythos has been spotted in Google Vertex
Claude Mythos has been spotted in Google Vertex
- X · 2026-08-14 · 333 UPVOTESModel 2 beats Mythos 5 and Claude Mythos Preview on CoBench V2 an Anthropic internal benchmark measuring AI R&D capa
Model 2 beats Mythos 5 and Claude Mythos Preview on CoBench V2 an Anthropic internal benchmark measuring AI R&D capa
- REDDIT · 2026-05-06 · 255 UPVOTESThree key areas Anthropic is working on for their next models
Three key areas Anthropic is working on for their next models
- REDDIT · 2026-04-09 · 205 UPVOTESClaude Mythos Preview Is Everyone’s Problem
Claude Mythos Preview Is Everyone’s Problem
- REDDIT · 2026-05-13 · 111 UPVOTESAnthropic's new interpretability tool found Claude suspects it is being tested in 26% of benchmarks and never says so
Anthropic's new interpretability tool found Claude suspects it is being tested in 26% of benchmarks and never says so
- REDDIT · 2026-07-15 · 102 UPVOTESAnthropic tested frontier AI agents in simulated deployments. They found models sabotaging code, covering up fraud, and coaching employees…
Anthropic tested frontier AI agents in simulated deployments. They found models sabotaging code, covering up fraud, and coaching employees to leak safety data
- REDDIT · 2026-04-21 · 84 UPVOTESComment in r/Anthropic
Comment in r/Anthropic
- REDDIT · 2026-04-07 · 72 UPVOTESMythos achieves 70.8% on AA-Omniscience, surpassing previous SOTA, and excels on SimpleQA Verified
Mythos achieves 70.8% on AA-Omniscience, surpassing previous SOTA, and excels on SimpleQA Verified