Prompt Builder

Prompt Builder renders a reusable prompt template by substituting named variables enclosed in double curly braces (for example {{topic}}). As you type a template, the tool automatically detects every unique {{name}} token in the text, lists them as clickable chips, and lets you define a value for each variable. The fully substituted result is shown live with a character count and can be copied to the clipboard.

1. Enter your template text in the Template area, using {{variable}} placeholders where values should go. 2. Below the textarea, the Detected Variables row lists every unique {{name}} found in the template; click any chip to insert that token at the end of the template. 3. Under Variables, click Add variable to create a row, type the variable name (matching the placeholder, without braces) in the left field, and enter its replacement value in the right field. Add or remove rows with the trash icon as needed. 4. The Result card updates instantly with substituted text, a character count, and a Copy button to send the rendered prompt to the clipboard.

The renderer scans the template and replaces every {{name}} token with the value from a matching variable row. If a variable has a name but no value, the original {{name}} placeholder is left in the result so missing inputs stay visible. Names are matched literally (case-sensitive, underscores allowed, alphanumeric only). Tokens that have no corresponding variable row are left untouched, so you can safely mix filled and pending placeholders.