What is an AI prompt generator?

An AI prompt generator turns a plain-language description of what you want into a structured prompt a language model can follow reliably. It supplies the parts people usually leave out — the role, the background context, the output format, the constraints and the success criteria — and orders them the way the target model reads best.

Is WriteMyAIPrompt free?

Yes, with no sign-up, no account and no API key. The compiler runs entirely in your browser, so there is no per-user cost to cover and nothing to upsell.

Which AI models does it support?

Claude, ChatGPT, Gemini, Grok, Llama, image models such as Midjourney and Stable Diffusion, and a portable format for anything else. Each gets the syntax it follows most reliably: XML tags for Claude, markdown headings for ChatGPT, a front-loaded task for Gemini, and a comma-delimited descriptor stack for image models.

How do I write a good AI prompt?

State the task specifically, supply the background the model cannot infer, define the shape of the answer, bound it with explicit rules, show one example of a correct result, and say how you will judge it. Those six things are what this tool scores, and missing any of them is why most prompts underperform.

Does it store my prompts?

No. Prompts are compiled on your device and never sent to a server. Your last twenty prompts are kept in your own browser so you can return to them, and you can clear them at any time.

Free AI prompt generator

Turn a rough idea into a prompt that actually works — and see exactly what is still missing.

WriteMyAIPrompt is a free tool that turns a rough idea into a structured, professional-grade AI prompt for Claude, ChatGPT, Gemini, or an image model — with no sign-up and no cost. Describe what you want in plain language and it returns a structured prompt with the role, context, constraints, and output format filled in — plus a score showing exactly what is still missing.

No sign-upNo API keyRuns in your browserPrompts, templates and agentsFree forever

What do you want the AI to do?

Try:

What should it build?

A one-off prompt for this task

Which model is this for?

Your prompt

Writing · ~203 tokens

<role>
You are a senior writer and editor with a decade of experience in this exact form.
</role>

<constraints>
- Write in plain, direct prose. Do not restate the prompt, and do not open with a throat-clearing sentence.
- Vary sentence length. Do not begin consecutive sentences with the same word or structure.
- Do not invent facts, statistics, quotations, or attributed opinions.
</constraints>

<output_format>
Respond in Markdown. Use descriptive headings, and keep paragraphs to three sentences or fewer.
</output_format>

<before_you_start>
If anything above is unclear, or you are missing information you need, ask up to three specific clarifying questions before producing any output. Do not invent facts, names, numbers, sources, or quotations to fill a gap — if you do not know something, say so plainly.
</before_you_start>

Now produce the output described above.

5 free per day

Filled in for you: archetype, outputType, role, format, reasoning, verb. Open “Add detail” to override any of it.

Prompt strength

0/100 · Weak

Specificity: 0/25
Context: 0/15
Output format: 0/20
Constraints: 0/15
Examples: 0/15
Success criteria: 0/10

Raise the score

This brief is thin, so the prompt tells the model to ask before guessing rather than inventing details to fill the gap.

Press ⌘K for commands, ⌘↵ to copy.

What makes an AI prompt strong?

A strong prompt is specific about the task, supplies the background the model does not have, defines the shape of the answer, bounds it with explicit rules, shows an example, and states how the result will be judged. WriteMyAIPrompt scores every prompt against those six dimensions, weighted as follows.

Specificity25 points: How precisely the task is stated: its length, whether it names concrete details such as numbers or proper nouns, and whether it leans on vague qualifiers.
Context15 points: Whether the model is given the background and the intended reader it needs.
Output format20 points: Whether the shape of the answer is defined: format, output type, length, and tone.
Constraints15 points: How many explicit rules and exclusions bound the output.
Examples15 points: Whether the prompt shows the model what a correct answer looks like.
Success criteria10 points: Whether the prompt states how the output will be judged.

The score rates the brief you supply, not the prompt the tool produces. Restructuring your words adds no information you did not give, so the number only moves when you add something real. The full rubric is published here.

Common questions

What is an AI prompt generator?: An AI prompt generator turns a plain-language description of what you want into a structured prompt a language model can follow reliably. It supplies the parts people usually leave out — the role, the background context, the output format, the constraints and the success criteria — and orders them the way the target model reads best.
Is WriteMyAIPrompt free?: Yes, with no sign-up, no account and no API key. The compiler runs entirely in your browser, so there is no per-user cost to cover and nothing to upsell.
Which AI models does it support?: Claude, ChatGPT, Gemini, Grok, Llama, image models such as Midjourney and Stable Diffusion, and a portable format for anything else. Each gets the syntax it follows most reliably: XML tags for Claude, markdown headings for ChatGPT, a front-loaded task for Gemini, and a comma-delimited descriptor stack for image models.
How do I write a good AI prompt?: State the task specifically, supply the background the model cannot infer, define the shape of the answer, bound it with explicit rules, show one example of a correct result, and say how you will judge it. Those six things are what this tool scores, and missing any of them is why most prompts underperform.
Does it store my prompts?: No. Prompts are compiled on your device and never sent to a server. Your last twenty prompts are kept in your own browser so you can return to them, and you can clear them at any time.

Browse prompts by category

Not sure where to start? The prompt library groups every use case by what you are trying to do.