Prompt Variable Tester — Template Preview

Write a prompt template with {{variables}} and provide values to preview the filled prompt.

How to use
  1. Write your prompt template with {{variable}} placeholders.
  2. Enter variable values as key=value pairs, one per line.
  3. See the filled prompt in the output preview.
Frequently asked questions
What placeholder syntax is supported?
Double curly braces: {{variable_name}}. Names can include letters, numbers, and underscores.
How do I provide variable values?
One per line in key=value format, e.g. name=Alice on its own line.
What if a variable is missing?
Missing variables are left as {{placeholder}} in the output so you can spot gaps.
Is my prompt sent to a server?
No. Template rendering happens entirely in your browser.
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