Regex Tester – I7 Pixel

// Developer Tools

Regex Tester

Test and debug regular expressions with live match highlighting, capture groups, replace preview, and a built-in cheatsheet. Zero latency — runs entirely in your browser.

✓ Free · No Upload Live Highlighting Capture Groups · Replace 100% Client-Side

.*? RegEx

🔍 Regular Expression Enter a pattern to begin

Enter a regex pattern above

📝 Test String 0 chars

✅ Matches 0 matches

Total Matches

Capture Groups

Match Positions

—

First Match At

—

#	Match	Index	Length	Groups
Enter a pattern and test string to see matches

♻️ Replace Preview

Replace

Result

Enter a replacement pattern above to preview the result…

💡 Use $1, $2… to reference capture groups. Use $& for the whole match.

📖 Cheatsheet

Anchors

Start of string/line

End of string/line

Word boundary

Non-word boundary

Character Classes

Any char (not newline)

Word char [a-zA-Z0-9_]

Non-word char

Digit [0-9]

Non-digit

Whitespace

Non-whitespace

[a-z]

Custom char class

[^abc]

Negated class

Quantifiers

0 or more (greedy)

1 or more (greedy)

0 or 1 (optional)

{n,m}

Between n and m times

Lazy (non-greedy)

Lazy 1 or more

Groups

(…)

Capture group

(?:…)

Non-capture group

(?=…)

Positive lookahead

(?!…)

Negative lookahead

(?<=…)

Positive lookbehind

(?<!…)

Negative lookbehind

a|b

Alternation (or)

Backreference to group 1

⚙️ Options

Flags

Global (g) — find all matches

Case-insensitive (i)

Multiline (m) — ^ and $ per line

Dotall (s) — . matches newline

Display

Highlight capture groups