Code Snippet Formatter Free Online Tool 2026

Last updated March 22, 2026

Code Snippet Formatting

A code snippet formatter takes raw code and applies consistent formatting: indentation, spacing, line length limits, and language-specific conventions. Well-formatted snippets are easier to read in documentation, blog posts, and presentations. The key is using the right formatter for each language.

Formatting Principles

• Consistent indentation: 2 spaces for JS/HTML/CSS, 4 spaces for Python, tabs for Go.
• Line length: Keep lines under 80–100 characters for readability in narrow contexts.
• Trailing whitespace: Remove all trailing spaces and ensure a final newline.
• Blank lines: Use blank lines to separate logical sections, but not excessively.
• Comments: Keep comments in formatted output — they explain intent.

Formatting with Prettier API

import * as prettier from 'prettier';

async function formatSnippet(code, language) {
  const parserMap = {
    javascript: 'babel',
    typescript: 'typescript',
    css: 'css',
    html: 'html',
    json: 'json',
    markdown: 'markdown',
    yaml: 'yaml'
  };

  const parser = parserMap[language];
  if (!parser) return code; // unsupported language

  return prettier.format(code, {
    parser,
    printWidth: 80,
    tabWidth: 2,
    semi: true,
    singleQuote: true,
    trailingComma: 'es5'
  });
}