Highlight RegExp Matches in Text

Want to quickly spot specific patterns in your content? The Highlight RegExp Matches in Text Tool helps you locate and highlight regular expression matches live as you type. It’s great for emails, IDs, numbers, or anything you can define with RegExp. Best of all, you can change the pattern and flags anytime and see results immediately.

Paste your input above or import a file below.
No file chosen
Supported file types: .txt, .csv, .tsv, .json, .log, .html, .md, .xml, .yml, .yaml, .css
Total matches: 0
Options

How to Use:

  1. Paste or type your content into the Input Text box.
  2. (Optional) Click Choose File to load a .txt, .csv, .log, .json, or other plain-text file.
  3. In the Options box:
    • Enter your RegExp Pattern (e.g. \d+ for numbers or [a-z]+ for lowercase words).
    • Set any Flags like g (global), i (case-insensitive), or m (multiline).
  4. Matches are instantly highlighted in the Highlighted Output box with yellow <mark> highlights.
  5. Use Copy Output to copy the plain text version, or Export to File to download it.
  6. Click Clear All to reset the inputs and output area.

What Highlight RegExp Matches in Text Tool can do:

This tool gives you a fast and flexible way to visually test regular expressions. Unlike static regex testers, it highlights each match live, so you don’t have to guess where your pattern is working. You control the pattern and flags, and the highlights appear without modifying the base content. Invalid patterns won’t crash the tool instead, you’ll see a clear error message that helps you fix it.

Example:

Input:

Contact emails: [email protected], [email protected]

RegExp Pattern:

[a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,}

Flags:

g

Output (visual):

Contact emails: <mark>[email protected]</mark>, <mark>[email protected]</mark>

Total matches:

2

Common Use Cases:

Whether you’re testing a new pattern, debugging complex expressions, or cleaning up structured text, this tool makes regex practical. Developers often use it to validate inputs like emails or UUIDs. Writers use it to find repeated phrases or formatting tags. Data analysts love it for matching IDs, numbers, or tokens in messy text. Whatever your use case, you’ll find this tool helps you move faster and more confidently.

Useful Tools & Suggestions:

Once you’ve pulled what you need with Extract RegExp Matches from Text, Highlight RegExp Matches in Text helps you visualize those patterns right inside the original content. It’s especially useful when you’re reviewing matches or building an interface that needs clear feedback on regex behavior.

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