Question 1

How do I use the regex tester?

Accepted Answer

Enter your pattern and flags in the regex bar, type sample text in the CodeMirror editor, then switch between Match, Replace, Explain, and Code tabs to see live results. Use the template library to insert common patterns and edit them as needed.

Question 2

Which regex features are supported?

Accepted Answer

The tool uses the browser’s native RegExp (ECMAScript). Common metacharacters, quantifiers, classes, groups, and lookaround are supported, along with g, i, m, s, y, u flags. The Explain tab is heuristic; validate with actual matches for complex patterns.

Question 3

How should I read the match list?

Accepted Answer

Each row shows the matched text, its index, and capture groups. Matches are highlighted in the editor; click a row to jump there with a short temporary highlight.

Question 4

Replace preview vs apply replace?

Accepted Answer

Replace preview shows the result of applying your replacement string to the whole text without changing the editor. Apply replace writes that result back into the test editor so you can keep iterating.

Question 5

What does code generation produce?

Accepted Answer

Sample snippets for JavaScript, Python, PHP, Java, and C# using your current pattern and flags (match/replace/test examples). Copy and adapt them in your project.

Question 6

Can I edit templates after inserting?

Accepted Answer

Yes. Templates only pre-fill the pattern field; you should still tune them for your data formats and security rules.

Online Regular Expression Tester