Prompt Template Filler & Prompt Diff

Paste a prompt template to get an input for every variable and a live preview of the filled prompt, or diff two versions of a prompt to see exactly which words changed.

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Template
Variables
Filled prompt

    

  


  
  

    
Compare two prompt versions

    

      
Version A (before)

      
Version B (after)

    

    

    
Word diff

  


  

    
Frequently Asked Questions

    
Which placeholder syntaxes are supported?
Mustache/Jinja-style {{name}}, Python f-string / LangChain-style {name}, JavaScript template ${name}, and shell-style $name. Pick the style your code uses; Auto picks the first one that appears in the template.

    
Why diff prompts word by word?
Small wording changes in system prompts can change model behaviour. A word-level diff makes every edit visible, which is useful for reviewing prompt changes the same way you review code.

    
Is my prompt stored anywhere?
No. Templates and values stay in your browser. The Share button puts the template (not the variable values) in the URL only if you click it.

  




  
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    Prompt Template & DiffFill {{vars}}, compare versions