See your file's fake
Paste or drop your rules file. See the same-length fake that the placebo arm would put in its place.
Your file stays in this page. Building the fake calls no model and stores no file data.
The preview needs JavaScript. You can measure your file with the CLI:
npx driftproof run <path> --suite tasks.json --placeboWhich file and mode?
Choose context mode for CLAUDE.md or AGENTS.md. Choose skill mode for a skill containing only SKILL.md. Bundled files change a skill's seed, so this preview does not match skills with other bundled files.
Use a UTF-8 Markdown file. A selected or dropped file keeps its original bytes, including line endings. Pasted text uses the browser's line endings.
The fake uses the runner's pinned corpus and algorithm. It is a preview, not a measurement or a receipt. It does not tell you whether your file helps.
After loading, the reader makes no requests. It keeps file data out of the address, cookies and browser storage.
To measure a context file, replace the path and supply your tasks in tasks.json. For a skill, use its directory and omit the suite flag. Measurement runs can call models and incur costs.