How do I run regex substitution and string replacement?

DevToolsAtlas provides a live regex substitution box where you can test replacing matched patterns with static text or backreferences in real time.

Regex Developer Suite

Interactive Regex Matcher, Debugger & Builder

Test regular expressions, run live pattern substitution, and generate JavaScript, Python, & Java code snippets.

Common Pattern Presets:

Regex Pattern

Flags

Test String Input

1 lines | 92 bytes

Substitution / Replacement String:

Matches Found (2)

support@devatlas.comcontact@workdayatlas.com

Substituted Text Output

Contact developer support at [REDACTED_EMAIL] or [REDACTED_EMAIL] for inquiries.

Export Code Snippet

// JavaScript Regex Matching
const pattern = /[a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,}/g;
const text = `Contact developer support at support@devatlas.com or contact@workdayatlas.com for inquiries.`;

const matches = text.match(pattern);
console.log("Matches:", matches);

// Substitution / Replace
const replacedText = text.replace(pattern, "[REDACTED_EMAIL]");
console.log("Substituted Text:", replacedText);

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Frequently Asked Questions

JavaScript uses native RegExp syntax with flags (`g`, `i`, `m`, `u`). Python uses the `re` module with raw strings `r""` and `re.findall()`. Java uses `java.util.regex.Pattern` and `Matcher` classes with double-escaped backslashes (`\\d`).

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