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.

For Claude, ChatGPT, Gemini, Grok, Llama and image models

Free AI prompt generator

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-up
No API key
Runs in your browser
Free forever

What do you want the AI to do?

0 wordsMore detail scores higher

Or start from an example

What should it build?

A one-off prompt for this task

Which model is this for?

Your prompt

For Claude

Your prompt builds here as you type.

Describe the task in plain words. The role, structure, rules and output format are filled in for Claude, and the score below shows what is still missing.

Prompt strength

Scored out of 100 as you type, against six checks.

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

Press ⌘K for commands, ⌘↵ to copy.

How does the prompt generator work?

WriteMyAIPrompt compiles a prompt from your description in three steps, entirely in your browser. No request leaves the page until you choose to send the result somewhere.

Describe it
Say what you want in plain words, the way you would brief a colleague. One sentence is enough to start.
Sharpen it
Answer a few one-tap questions picked for your task — audience, tone, length, must-haves. The score shows what is still missing.
Copy or run it
Copy the prompt, share it as a link, or open it straight in ChatGPT, Claude or Gemini with one click.

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 pts: 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 pts: Whether the model is given the background and the intended reader it needs.
Output format20 pts: Whether the shape of the answer is defined: format, output type, length, and tone.
Constraints15 pts: How many explicit rules and exclusions bound the output.
Examples15 pts: Whether the prompt shows the model what a correct answer looks like.
Success criteria10 pts: 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.