Free Client-Side Tool
AI Prompt Analyzer
Test and audit any prompt against concrete quality signals: role clarity, action verbs, context, output format, constraints, and vague filler words. 100% private in your browser.
Paste your prompt to analyze
The 7 signals of a high-performing prompt
Unlike human readers, language models cannot infer unstated intent. When you paste a vague request like "write a blog post", the AI must guess the tone, target audience, formatting, and depth. The Prompt Analyzer checks for seven concrete signals:
| Signal | Why it matters | How to fix if missing |
|---|---|---|
| Role & Persona | Anchors the AI in domain-specific vocabulary and expert perspective. | Open with Act as an expert [profession] or You are a specialist in.... |
| Clear Action Verb | Eliminates passive vagueness and tells the model the exact deliverable. | Lead with imperative verbs: Write, Draft, Audit, Summarize. |
| Context & Audience | Prevents generic advice by anchoring the response to specific constraints and readers. | Specify who will read the output or paste relevant background material. |
| Format Specification | Forces the response into a structured layout that is easy to skim and apply. | Request a Markdown table, 5 bullet points, or step-by-step numbered list. |
| Constraints & Limits | Sets negative guardrails to suppress clichés, hallucinations, and unnecessary fluff. | State length ceilings (under 300 words) and things to avoid (do not use buzzwords). |
| Vague Filler Words | Subjective adjectives like "cool", "nice", or "good" lack measurable meaning to an AI. | Replace vague qualifiers with concrete criteria and tone descriptions. |
| Optimal Length | Prompts under 10 words leave too much to chance; prompts over 400 words risk losing key instructions. | Aim for 25 to 350 words of clear, modular instructions. |
Explore all free prompt tools
Prompt Idea Generator
No prompt yet? Get a random, ready-to-use one from the library, filtered by category and AI tool.
Open Generator →Prompt Optimizer
Turn vague instructions into structured, production-ready prompts using the site's 5-part framework. Compare before and after side-by-side.
Open Optimizer →Prompt Converter
Translate prompt framing between ChatGPT, Claude, Midjourney parameter tags, and video tools like Veo and Kling.
Open Converter →Frequently asked questions
How does the Prompt Analyzer work?
The tool evaluates pasted prompts client-side in your browser using concrete heuristic signals: role definition, action verbs, background context, output formatting, negative constraints, vague filler words, and optimal length.
Does the analyzer send my prompt to a server or external AI?
No. Everything runs 100% locally in your browser using vanilla JavaScript. No external AI APIs are called, and your text is never transmitted or saved.
Why does the tool show a checklist instead of a numerical score?
Arbitrary numbers like "87/100" give a false impression of precision. Prompt quality depends on concrete building blocks (role, context, format, constraints). A checkable signal list shows exactly what is present and what to add.
Can I use this tool for image or video prompts?
Yes. Image and video prompts also benefit from clear subjects, style descriptors, lighting context, and parameter constraints. For tool-specific parameter conversions, use our Prompt Converter.