Claude AI Detector

Claude, developed by Anthropic, has become one of the most capable AI writing assistants available. Claude's output is distinctive: it tends to be measured and thoughtful in tone, frequently uses qualifying language ("It's worth noting," "This is a nuanced topic"), and often presents multiple perspectives before settling on a position. Claude also has a characteristic tendency to be transparent about limitations and uncertainties, which paradoxically makes its writing feel more human-like and harder to detect with simple tools.

Coda One's Claude AI Detector is built to catch these specific patterns. Our statistical model identifies Claude's signature sentence structure -- typically longer, more complex sentences with multiple clauses compared to other AI models. The pattern model detects Claude-specific hedging phrases, its distinctive paragraph-opening styles, and its tendency to use semicolons and em dashes more frequently than human writers typically do. The ensemble model combines these signals for comprehensive detection.

Claude's writing quality has improved dramatically across versions (Claude 1 through Claude 3.5 Sonnet and beyond), making detection progressively harder. Our multi-model approach is designed to handle this evolution. Whether you're checking content potentially written by Claude Instant, Claude 3 Haiku, Claude 3.5 Sonnet, or newer versions, the detector identifies the underlying Anthropic model patterns that persist across versions. The tool is completely free and unlimited -- analyze as many texts as you need without signup or daily caps.