Prompt Formatter
Format a prompt as chat messages, XML tags or Markdown.
Processed locally in your browser. Nothing you paste is sent anywhere.
- Three output shapes from one input, so you can try each without retyping.
- Produces a valid chat-messages array ready to drop into an API call.
- Runs in your browser — prompts aren't uploaded.
Why this is private
- Processed locally in your browser. Nothing you paste is sent anywhere.
- Open your browser's DevTools → Network tab while using this tool — you won't see a request carrying your input, because it never leaves your device.
- Nothing you enter is uploaded to a server or shared with us — the processing happens entirely on your device.
Overview
Formats a system/user prompt into common shapes used when calling LLM APIs — a chat-messages JSON array, XML-tag-wrapped content (a pattern Claude responds well to), or plain Markdown sections.
How to use it
- 1Pick an output format.
- 2Fill in your system prompt and content.
- 3Copy the formatted result.
Frequently asked questions
What people use it for
Move a prompt between providersReshape a working prompt into the chat-array format another SDK expects.
Wrap context in XML tagsDelimit documents or examples with tags, a structure Claude follows well.
Turn a draft into a templateFormat loose notes into clear system and user sections.
Prepare a prompt for version controlKeep a readable Markdown copy alongside the code that sends it.
Related tools
All ai & llm toolsPrompt ChunkerSplit long text into token-bounded chunks, with optional overlap between them.Token CounterExact token counts for OpenAI models, plus calibrated per-model estimates for Claude, Llama, Gemini and Mistral.Context Window CalculatorSee how much of a model's context window your text uses.AI API Cost CalculatorEstimate monthly LLM API costs from token volume.
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Prompt Formatter