Find and Replace Online — Batch Rules and Regex

What it is

Most editors let you find and replace one thing at a time. Cleaning up real text usually takes several passes: fix the date format, rename a product, collapse double spaces, swap straight quotes. This tool keeps all of those passes as a list of rules and runs them in one go, top to bottom, every time you edit the text or a rule.

Each rule shows how many replacements it made, and a summary line gives the total, so a rule that matched nothing (or far too much) stands out straight away. Rules can be plain text or JavaScript regular expressions with capture groups, and the whole-word option understands every script, not just English. The page opens with a short sample and two rules so you can see the result before typing anything.

How to use

1. Paste your text into the Text box.
2. For each rule, fill in Find and Replace with, then tick Regex, Match case or Whole word as needed.
3. Press Add rule for more rows (up to 20) and the ✕ button to drop one.
4. Check the count next to each rule title and the total above the result.
5. Copy the result when it looks right.

How it works

• Order: rules run from top to bottom and each one works on the previous output. Rules with an empty Find are skipped.
• Plain mode: Find is matched literally and every occurrence is replaced. A $ in the replacement is inserted as a dollar sign.
• Match case: off by default, so upper and lower case are treated alike (using Unicode case folding).
• Regex mode: JavaScript syntax with the g, m and u flags. ^ and $ match at the start and end of every line, and . matches any single character except a line break, including a whole emoji. In the replacement, $1 and $2 insert groups, $ a named group, $& the whole match and $$ a single dollar sign.
• Whole word: a match only counts when the character right before and right after it is not a Unicode letter, combining mark, digit or underscore. It works with regex rules too.
• \n and \t (on by default): in replacements and in plain-mode Find, \n becomes a line break, \t a tab and \ one backslash; other backslashes are kept. A regex Find keeps ordinary regex escapes.
• Safety: everything runs in a Web Worker with a 2-second limit; the result refreshes 250 ms after you stop typing.
• Limits: 200,000 characters of text, 20 rules, 1,000 characters per Find or Replace field and 1,000,000 characters of output.

Examples

Text	Rule	Result
Starts 2026-10-05	Regex (\d{4})-(\d{2})-(\d{2}) → $2/$3/$1	Starts 10/05/2026
cat catalog (cat)	cat → dog, whole word	dog catalog (dog)
Cat cat CAT	cat → dog, match case	Cat dog CAT
price 1.5	1.5 → $1 (plain)	price $1
a, b, c	, → \n	a, b and c on separate lines
apple	apple → pear, then pear → plum	plum