Anthropic has released a tool capable of identifying whether files, such as images or audio, were generated or processed by Claude.
Product LaunchesAnthropicClaude
Anthropic Releases Tool to Verify Files Created with Claude
This article is a translation. Read the Japanese original
This tool identifies content credentials embedded within the files.
When Claude generates supported file formats (such as .png, .jpg, and .svg), it adds an encrypted signature annotation to the metadata. This is based on the C2PA industry standard, a technology also adopted by camera manufacturers and photo editing software.
The tool operates within the browser, ensuring that files are not transmitted from the device. The identification results indicate only whether Claude was involved, without identifying the user's personal information.
Regarding the detection of watermarks embedded in text, a detection API is currently being provided as a private preview for target organizations in accordance with EU law.
Source: Check if a file was made with Claude (Hacker News Frontpage, 2026-09-02)