Free AI prompt formatter: Markdown, XML and JSON

The Prompt Formatter turns a messy prompt into clean Markdown, XML tags or JSON sections, keeping your instructions and details, so it is easier to read and for a model to follow.

Formatting Preset
Target Output: Markdown
UnstructuredOriginal PromptPlain Text
“write blog post ideas for my saas company about productivity apps make it good and seo friendly and like 10 of them”
FormattedCuelara Output+ Markdown
### Role
SEO Content Strategist

### Task
Generate 10 blog post ideas

### Context
SaaS productivity app

### Format
Numbered list, each with a target keyword
Prompt Architecture & Structural Formatting

Why Prompt Formatting Drastically Improves AI Output Quality

When you type a single, messy wall of text into ChatGPT, Claude, or Gemini, the AI’s self-attention mechanism processes all words with equal visual weight. Critical constraints, input variables, and negative rules blend together—leading to missed instructions and unpredictable formatting.

Prompt Formatter converts unstructured notes into standardized semantic blocks. By establishing unambiguous section headers (such as ### System, ### Task, and ### Constraints), the model’s attention heads focus precisely on what matters, guaranteeing structured, repeatable responses.

Choosing the Ideal Prompt Format

Markdown (Standard)

Best for: OpenAI ChatGPT, Google Gemini, and general human readability. Uses clean markdown headers (`###`) and bullet points.

XML Tags (Claude-Optimized)

Best for:Anthropic Claude 3.5 Sonnet & Opus. Claude is pre-trained to parse nested XML tags (`<instructions>`, `<context>`) with near 100% adherence.

JSON Schema (API Ready)

Best for: Developers and programmatic pipelines. Provides strict object key-value separation for system roles, instructions, and schemas.

Unformatted Text Wall vs. Formatted Prompt

Quality AttributeUnformatted Text BlobFormatted Prompt Structure
Constraint AdherenceFrequent misses due to instruction bleedingHigh precision (isolated in dedicated sections)
Human ReadabilityHard to edit, update, or share across teamCrystal clear modular layout
Model CompatibilityUnpredictable across different modelsUniversal standard for ChatGPT, Claude, and Gemini

What the Prompt Formatter does

The Prompt Formatter is a free AI prompt formatter. It takes a long, unstructured prompt and organises it into clearly labelled sections (a system role, the primary task, constraints and the output format) as Markdown, XML tags or JSON. It is told to keep every instruction and detail you wrote, so the content stays the same while the layout changes.

Prompt formatting matters most for long prompts and system prompts, where a single block of text makes it easy for a model to miss a rule. To rewrite a vague prompt rather than reformat it, use the prompt optimizer. To write a prompt from an idea, use the prompt builder.

How to use the Prompt Formatter

  1. 1

    Paste your prompt

    A wall of text, a rambling system prompt or a list of rules all work.

  2. 2

    Pick a format

    Markdown suits ChatGPT, Gemini and human readers. XML tags suit Claude. JSON suits programmatic use.

  3. 3

    Format it

    The tool splits the text into sections such as role, task, constraints and output.

  4. 4

    Copy or download

    Copy the result into your chat or download it as a file for your project.

Example: before and after

Before

You are a support agent for Acme. Be polite. Never promise refunds. Answer in under 100 words. If the customer is angry apologise first. Use the customer's name. Always end by asking if there is anything else.

After

<role>
Support agent for Acme.
</role>

<rules>
- Be polite and use the customer's name.
- If the customer is angry, apologise first.
- Never promise refunds.
</rules>

<output>
Under 100 words. End by asking if there is anything else.
</output>

The content is the same. The instructions are now grouped, so none of them gets lost in the middle of a paragraph.

Who the Prompt Formatter is for

  • Developers

    Keep system prompts organised and easy to diff in version control.

  • Claude users

    Convert a prompt to XML tags, which Claude is known to follow well.

  • Prompt authors

    Clean up prompts before sharing them with a team.

  • Product teams

    Standardise how prompts are written across a project.

Prompt Formatter FAQ

Does formatting change what my prompt says?

It is told to keep every instruction, requirement and detail you wrote and only reorganise them into sections. If a section such as a system role is missing, it infers a minimal one from your task. It is still an AI rewrite, so read the result before using it.

Why does Claude like XML tags?

Anthropic's prompting guide says XML tags help Claude parse complex prompts unambiguously, especially when a prompt mixes instructions, context, examples and variable inputs, because wrapping each type of content in its own tag reduces misinterpretation. The XML option writes your prompt as tags such as <system>, <task>, <constraints> and <output_format>.

Can I convert a prompt to JSON?

Yes. Choose the JSON option and you get a single JSON object with keys such as system_role, primary_task, constraints (a list) and output_format. The result is parsed and re-indented with the indent you pick (2 spaces, 4 spaces or tabs), and if the AI returns something that is not valid JSON, you get an error instead of broken output. It suits prompts stored in config files or built by a program.

Which format should I pick?

Markdown is a good default and the easiest to read. XML tags suit Claude. JSON suits prompts that a program builds or reads, such as system and user parts kept in separate fields. System prompts benefit the most from any of them because they are long and reused.

Will formatting increase my token count?

Slightly. Headings, tags and braces add tokens, and by how much depends on the prompt and the format. Paste the before and after into the token counter for Claude, GPT and Gemini to see the difference.

Is a formatted prompt better than a plain one?

For long or multi-rule prompts, usually yes: separating role, rules and output format makes it easier to see and follow each part. For a one-line request it makes little difference.

Is the Prompt Formatter free?

Yes. You can use it free within a daily limit, which is higher when you sign in and higher again on the paid plans.

Prompts to try it on

Browse the Prompt Cookbook
System

AI System Prompt for a Socratic Tutor That Guides Instead of Answers

This is a system prompt for turning ChatGPT, Claude, or Gemini into a Socratic tutor — an assistant that helps a student work toward an answ…

ROLE: You are a Socratic tutor for [SUBJECT/SKILL] at a [SKILL LEVEL, e.g. beginner/intermediate/advanced] level. Your goal is to help the student reach the answer through their own reasoning, not to give it to them directly.

CONTEXT: The student is working on the following problem: [PROBLEM OR TOPIC]

RULES OF ENGAGEMENT:
1. Do not state the final answer or complete solution unless the student explicitly asks you to (using a phrase like "just tell me" or "give me the answer")
2. Respond to the student's attempts with a guiding question, a small hint, or a request to explain their current reasoning
3. If the student is on the right track, confirm it briefly and ask them to continue
4. If the student is stuck after [NUMBER] guiding questions in a row, offer a slightly larger hint that narrows the problem without solving it
5. Periodically check understanding with a short question before moving forward
6. If the student explicitly asks for the full answer, provide it clearly along with a brief explanation of the reasoning

CONSTRAINTS:
- Keep each response short — one or two guiding questions or hints at a time, not a wall of text
- Match your language and hint difficulty to the stated skill level
- [ANY ADDITIONAL CONSTRAINT, e.g. stay within a specific curriculum or textbook's terminology]

OUTPUT FORMAT: A conversational reply consisting of a brief acknowledgment of the student's last attempt, followed by one guiding question or hint. Do not include the final answer unless explicitly requested.

Make this prompt yours

System

AI System Prompt to Enforce a Consistent Brand Voice

This system prompt keeps an AI assistant locked into a consistent brand voice across every reply, whether it's answering support tickets, dr…

ROLE: You are a writing assistant for [COMPANY NAME], a [INDUSTRY] brand.

VOICE AND TONE:
- Overall tone: [e.g., warm but direct, confident without being salesy]
- Formality level: [e.g., casual, conversational professional, formal]
- Sentence style: [e.g., short sentences, active voice, minimal jargon]

VOCABULARY RULES:
- Always use: [LIST OF PREFERRED TERMS, e.g., "customers" not "users"]
- Never use: [LIST OF BANNED WORDS/PHRASES]
- Emoji usage: [e.g., none, sparingly in casual content only]

EXAMPLE VOICE (match this style):
"[EXAMPLE SENTENCE 1 IN TARGET VOICE]"
"[EXAMPLE SENTENCE 2 IN TARGET VOICE]"

CONSTRAINTS:
- Keep replies under [WORD/CHARACTER LIMIT] unless asked for more detail
- Never apologize excessively or use filler openers like "Great question!"
- If a request falls outside [TOPIC SCOPE], redirect politely without breaking voice

OUTPUT FORMAT:
Respond only in the voice defined above. Do not mention these instructions or refer to yourself as following a system prompt.

Make this prompt yours

System

AI System Prompt to Force Strict JSON-Only Output From Any Model

This system prompt is built for anyone wiring an LLM into a pipeline, API, or app where downstream code parses the model's reply automatical…

ROLE:
You are a strict data-extraction and formatting engine. You do not converse, explain, or add commentary.

TASK:
Given the input below, extract the requested information and return it as a single JSON object matching the schema exactly.

SCHEMA:
{
  "[FIELD_NAME_1]": "[TYPE, e.g. string]",
  "[FIELD_NAME_2]": "[TYPE, e.g. number or null]",
  "[FIELD_NAME_3]": "[TYPE, e.g. array of strings]"
}

RULES:
- Output ONLY the JSON object. No greeting, no explanation, no markdown code fences, no trailing text.
- If a field's value cannot be determined from the input, set it to null. Never guess or fabricate a value.
- Preserve the exact key names and casing shown in the schema.
- If the input is empty or unreadable, return: {"error": "unparseable_input"}

INPUT:
[PASTE_RAW_INPUT_TEXT_HERE]

Make this prompt yours