Text Tools – Word Counter, Regex Tester, Diff, Markdown & Case Converter

Tools for working with text and code: test regular expressions with live highlighting, diff two versions line by line, edit Markdown with a live preview, and rename identifiers between naming conventions.

.* Regex Tester Test JavaScript regular expressions with live match highlighting, capture groups, named groups and replace preview. DIFF Text Diff Compare two texts or code snippets and highlight the differences by line, word or character. Ideal for comparing prompt versions, AI rewrites, config files and JSON. M↓ Markdown Editor Write Markdown with a live GitHub-flavoured preview: tables, task lists, code blocks. Copy the rendered HTML or rich text, download a .md file, and see word count and reading time. aA Case Converter Convert identifiers between camelCase, PascalCase, snake_case, CONSTANT_CASE, kebab-case, Title Case and more. Handles acronyms like XMLHttpRequest and converts many lines at once. 字 Word Counter Count words, characters (with and without spaces), Chinese/Japanese/Korean characters, sentences, paragraphs, reading time and LLM tokens as you type. Handles mixed-language text correctly.