Free tool

Prompt Auditor

Score your system prompt on structure, specificity, edge cases, token efficiency, and cacheability.

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  • Scores structure, specificity, edge cases, token efficiency, and cacheability separately — not one vague number.
  • Every finding references something concrete in your actual prompt, with a specific fix.
  • Estimates the dollar savings from restructuring for prompt caching, using your real pricing and volume.
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Frequently asked questions

This tool is powered by Claude (Anthropic).

Prompt caching lets Anthropic reuse a previously-sent system prompt instead of reprocessing it, billing repeated (cached) tokens at a lower rate. A prompt that mixes variable content (dates, user data) into its static instructions breaks the cacheable prefix, so every request pays the full fresh-input rate instead.

Every run — including the prompt you paste — is logged the same way as any other Tool Platform run, for abuse prevention and diagnostics. It is not added to any list, shared, or used for anything beyond that. See our privacy policy for details.