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Anthropic

Claude Mythos Preview

Frontier

Anthropic•Released on 2026-04-07

Anthropic's most powerful model ever, released April 7, 2026 through Project Glasswing. Not publicly available due to cybersecurity capabilities. Achieved breakthrough performance: 93.9% SWE-bench Verified (+13pp over Opus 4.6), autonomously discovered zero-day vulnerabilities in every major OS and browser. Internal codename was 'Capybara'. Anthropic describes it as a 'step change in capabilities' and 'distinct model category' above Opus tier.

Core Specs

0K
Context Window
0K
Max Output
✓
Reasoning
✗
Open Source
Multimodal Support
textimage

Scenario Scores

Coding
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Writing
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Translation
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Data Analysis
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Conversation
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Image Gen
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User Feedback Highlights

Based on community feedback. Hover to see original reviews.

− Timeline for general availability unknown− Dual-use risk: same capabilities that find vulnerabilities can exploit them− 40 organizations total have access− No API access for general users− Not publicly available - Project Glasswing partners only+ Strong agentic coding and reasoning+ 59% SWE-bench Multimodal (2x Opus 4.6)+ 77.8% SWE-bench Pro (20pp above GPT-5.4)+ Breakthrough cybersecurity capabilities - finds zero-days in major OS/browsers+ Highest SWE-bench Verified ever (93.9%)

Pros & Cons

Pros

  • +Highest SWE-bench Verified ever (93.9%)
  • +Breakthrough cybersecurity capabilities - finds zero-days in major OS/browsers
  • +77.8% SWE-bench Pro (20pp above GPT-5.4)
  • +59% SWE-bench Multimodal (2x Opus 4.6)
  • +Strong agentic coding and reasoning

Cons

  • −Not publicly available - Project Glasswing partners only
  • −No API access for general users
  • −40 organizations total have access
  • −Dual-use risk: same capabilities that find vulnerabilities can exploit them
  • −Timeline for general availability unknown

Reliability

Incidents (30d)0
Only available to 40 organizations via Project Glasswing

Pricing

Input (per 1M tokens)$0.00
Output (per 1M tokens)$0.00
Updated on 2026-04-08

Get Started

1Visit the provider's website
2Create an account
3Start using the model

Compare with Others

Claude Mythos Preview vs Claude Opus 4.7 →Claude Mythos Preview vs Claude Opus 4.6 →Claude Mythos Preview vs Claude Opus 4.5 →

Benchmarks

sweBenchVerified93.9%
sweBenchPro77.8%
sweBenchMultilingual87.3%
sweBenchMultimodal59%
terminalBench282%
usamo202697.6%
noteAll benchmarks represent significant improvements over Opus 4.6 and GPT-5.4%