Regex
Test regular expressions, inspect every match, and replace text with JavaScript RegExp syntax locally.
Open RegexDeveloper tool category
Use these tools when the problem is text rather than a structured data format. Test regular-expression behavior before replacing matches, or normalize words and identifiers into the naming style required by code, APIs, files, and documentation.
Common workflow
5 recommended starting points
Test regular expressions, inspect every match, and replace text with JavaScript RegExp syntax locally.
Open RegexConvert text between uppercase, lowercase, sentence case, title case, camelCase, PascalCase, snake_case, CONSTANT_CASE, dot.case, kebab-case, and URL slugs locally.
Open Case ConverterCheck whether a JavaScript regular expression matches your sample text and catch invalid pattern syntax locally.
Open Regex TesterFind every regular-expression match and inspect match indexes, captures, and named groups as structured JSON.
Open Regex MatcherPreview JavaScript regular-expression replacements with capture groups and configurable flags before changing source text.
Open Regex ReplacerPrimary utilities
2 core tools
Test regular expressions, inspect every match, and replace text with JavaScript RegExp syntax locally.
Convert text between uppercase, lowercase, sentence case, title case, camelCase, PascalCase, snake_case, CONSTANT_CASE, dot.case, kebab-case, and URL slugs locally.
Task-specific entry points
3 focused pages
Regex
Test regular expressions, inspect every match, and replace text with JavaScript RegExp syntax locally.
Check whether a JavaScript regular expression matches your sample text and catch invalid pattern syntax locally.
Find every regular-expression match and inspect match indexes, captures, and named groups as structured JSON.
Preview JavaScript regular-expression replacements with capture groups and configurable flags before changing source text.
Diagnose specific failures
1 topic hubs
Troubleshoot JavaScript regular-expression syntax, flags, anchors, quantifiers, groups, lookarounds, matching behavior, and replacements.
Understand the concepts
1 guides
Use this JavaScript regex cheat sheet for anchors, character classes, quantifiers, groups, lookarounds, flags, and replacement syntax with examples.