Model system cardsSystem cards document the capabilities, safety evaluations, and responsible deployment decisions for Claude models.ModelDateSystem cardClaude Haiku 5.5October 2026Read system cardClaude Sonnet 5.5September 2026Read system cardClaude Opus 5.5September 2026Read system cardClaude Fable 5.1 and Mythos 5.1September 2026Read system cardClaude Opus 5July 2026Read system cardClaude Sonnet 5June 2026Read system cardClaude Opus 4.8May 2026Read system cardClaude Fable 5 and Mythos 5June 2026Read system cardClaude Opus 4.7April 2026Read system cardMythos PreviewApril 2026Read system cardClaude Sonnet 4.6February 2026Read system cardClaude Opus 4.6February 2026Read system cardClaude Opus 4.5November 2025Read system cardClaude Haiku 4.5October 2025Read system cardClaude Sonnet 4.5September 2025Read system cardClaude Opus 4.1August 2025Read system cardClaude Sonnet 4 and Opus 4May 2025Read system cardClaude Sonnet 3.7February 2025Read system cardClaude Haiku 3.5 and Sonnet 3.5 (new)October 2024Read system cardClaude Sonnet 3.5June 2024Read system cardClaude 3March 2024Read system cardClaude 2July 2023Read system card