About

The Text Replacer is a high-precision utility designed for structural text modification and data sanitization. Unlike standard word processor functions, this tool implements a recursive batch processing engine that allows for complex, multi-stage transformations in a single pass. It addresses critical needs in software development, such as bulk variable renaming, and in content management, where specific formatting patterns must be strictly enforced across large datasets. By utilizing the RegExp engine with global flags, the tool ensures that no occurrence is missed while maintaining the integrity of the surrounding document structure.

Accuracy in text replacement is paramount when dealing with code or structured data like JSON or CSV. A single incorrect replacement can lead to syntax errors or data corruption. This tool mitigates such risks through its Smart-Case algorithm, which preserves the linguistic casing of the original match, and its Diff Highlighter, which provides a granular visual audit of every insertion and deletion before the final state is committed. It is optimized for scenarios where precision, speed, and safety are the primary requirements.

Formulas

The Smart-Case preservation logic follows a conditional mapping function f(m, r) where m is the match and r is the replacement string:

{

uppercase(r) if m = uppercase(m)titlecase(r) if m = titlecase(m)r otherwise

When executing batch rules, the tool applies a composition of functions:

Tn∏i=1= R_n(R_n-1(...(R₁(S))))

Where S is the source text and R_i is the i-th replacement rule in the sequence.

Reference Data

Token	Description	Example Pattern	Result Type
\d	Any numeric digit	\d+	Matches numbers
\s	Whitespace character	\s{2,}	Double spaces
\w	Alphanumeric word char	^\w+	First word
.	Any char (except newline)	.*	Wildcard
\b	Word boundary	\btest\b	Exact word
[A-Z]	Uppercase range	[A-Z]{2,}	Acronyms
(?=...)	Positive Lookahead	\d+(?=px)	Unit values
(?!...)	Negative Lookahead	q(?!u)	Edge cases
^ / $	Start / End of string	^\s+	Leading space
\n / \r	Line breaks	[\r\n]+	Newlines

Frequently Asked Questions

The tool analyzes the first two characters of the matched text. If both are uppercase, it applies full uppercase to the replacement. If only the first is uppercase, it applies title casing. If the first is lowercase, the replacement remains lowercase. This ensures that "User" becomes "Admin" and "user" becomes "admin" automatically.

Yes. The tool supports standard JavaScript regex backreferences. You can use $1, $2, etc., in the "Replace With" field to insert text captured by parentheses in your "Find" pattern. For example, finding (\d+)-(\d+) and replacing with $2/$1 will swap the values.

The tool is optimized for strings up to 2MB (roughly 2 million characters). Beyond this, browser-based regex engines may experience "catastrophic backtracking" depending on the complexity of your patterns. For massive datasets, we recommend breaking the text into smaller chunks.

If "Regex Mode" is enabled, you must escape special characters with a backslash. To find a literal period, use \.. To find a literal backslash, use \\. If "Regex Mode" is disabled, the tool treats all input as literal text and no escaping is required.