Free prompt optimiser
ChatGPT Prompt Optimiser
Turn a rough idea into a structured ChatGPT prompt: clear role, objective, context, constraints and output format, scored before you send it.
Runs with Local Rules, free, in your browser — no sign-up needed.
What this optimiser checks
- Whether the prompt states an audience or context ChatGPT can use
- Whether the goal is explicit rather than implied
- Whether concrete details, constraints or examples are present
- Whether the request tells ChatGPT what format to reply in
- Whether there's a way to check the reply is actually right
Example prompt
Write me a product description for my new coffee mug that I'm selling online.
ChatGPT answers the prompt in front of it, not the prompt you meant to write. A one-line request like the example above forces it to guess your audience, tone, length and format, so two people running the same vague prompt get two very different, equally unpredictable results.
Local Rules checks the prompt against seven signals — clarity, context, specificity, constraints, structure, output format and reasoning — and rewrites it into a Role / Objective / Context / Requirements / Output format / Quality check structure. That structure is what lets ChatGPT produce something usable on the first attempt instead of the third.
Frequently asked questions
- Does this send my prompt to OpenAI?
- Not unless you choose it. Local Rules analyses and rewrites your prompt entirely in your browser. If you switch to the ChatGPT/OpenAI direct option and enter your own API key, your prompt text is sent straight to OpenAI's API from your browser tab — never through our servers.
- Do I need an OpenAI account to use this?
- No. Local Rules needs no account, key or sign-up. An OpenAI key is only required if you deliberately choose the direct BYOK analysis instead of Local Rules.
- What's different about a ChatGPT-optimised prompt versus a generic one?
- The rewrite targets ChatGPT's instruction-following style: explicit formatting requests, numbered constraints, and a stated output shape, since ChatGPT follows literal structure closely when it's given one.
Free — no sign-up needed. Bring your own key for direct AI analysis, or stay local.