Anthropic's most powerful AI model ever built. A new tier above Opus with a step change in coding, reasoning, and cybersecurity capabilities.
Capybara introduces a fourth tier to Claude's lineup — larger, more intelligent, and more capable than Opus, which was previously Anthropic's most powerful offering.
Based on Anthropic's leaked internal benchmarks, Capybara dramatically outperforms Claude Opus 4.6 across every major category.
"Compared to our previous best model, Claude Opus 4.6, Capybara gets dramatically higher scores on tests of software coding, academic reasoning, and cybersecurity, among others."
— Anthropic draft blog post, leaked March 26, 2026 · Source: Fortune
Capybara scores dramatically higher than Opus 4.6 on coding benchmarks. Opus 4.6 already led industry rankings alongside GPT-5.3-Codex.
Significant improvements in academic reasoning tasks. Anthropic describes Capybara as a "step change" in overall intelligence.
"Currently far ahead of any other AI model in cyber capabilities" — can discover and exploit vulnerabilities faster than human defenders can patch them.
Anthropic calls it "the most capable we've built to date" — a new tier, not an incremental version update. Larger architecture than Opus.
All claims sourced from Anthropic's leaked draft blog post and official spokesperson statement.
Opus 4.6 scores are from Anthropic's published data. Capybara scores are unreleased — Anthropic confirms "dramatically higher" across the board.
Opus 4.6 scores sourced from Anthropic's published benchmarks. Capybara bars are illustrative — exact scores pending release. Cybersecurity: no public Opus 4.6 score; Anthropic states Capybara is "far ahead of any other AI model."
From the Fortune exclusive and Anthropic's official statements.
"Capybara is a new name for a new tier of model: larger and more intelligent than our Opus models."
Anthropic spokesperson confirmed it is "a step change" in AI performance and "the most capable we've built to date."
"Currently far ahead of any other AI model in cyber capabilities" — can exploit vulnerabilities faster than defenders can patch them.
Currently being trialed by select early access customers. Anthropic is "being deliberate" about its release given its power.
Described as "expensive to run" and positioned above Opus. Will be Anthropic's most premium model tier.
No official timeline. The leaked blog had a date, but Anthropic hasn't committed to any schedule post-leak.
Two ways to get ahead of the curve — managed cloud hosting or API access at competitive prices.
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Tracking every development around Claude Capybara.
Anthropic ships its previous flagship alongside OpenAI's GPT-5.3. Both flagged unprecedented cybersecurity capabilities.
~3,000 unpublished assets found in Anthropic's unsecured CMS, including the draft blog post announcing Claude Mythos and the Capybara tier.
Official statement: "a step change" and "the most capable we've built to date." Early access customers actively testing.
Capybara API expected for approved developers and enterprises, starting with cybersecurity-focused organizations.
Public API and Claude.ai access will follow Anthropic's rollout. MyClaw will offer managed hosting from day one.
Everything you need to know about Claude Capybara and Mythos.
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Not affiliated with Anthropic. Claude, Capybara, Mythos, Opus, Sonnet, and Haiku are trademarks of Anthropic, PBC. Last updated March 27, 2026.