Find and Replace Text Online: Plain Text and Regex Modes

You've just realized you need to change "Acme Corporation" to "Acme Inc." throughout a 50-page document. You could use your text editor's find-and-replace — but that requires opening the file, waiting for it to load, and hoping you don't accidentally replace something you shouldn't.

What if you need something more complex? Replace all phone numbers with [REDACTED]. Change every date format from MM/DD/YYYY to YYYY-MM-DD. Extract and normalize scattered data patterns.

The Find and Replace tool on DevStringTools handles both simple fixes and regex-powered transformations — all in your browser, all instant.

Why Find and Replace is Essential

Every developer, writer, and data worker needs bulk text replacement:

Code refactoring: Rename variables across a codebase
Content migration: Update terminology when rebranding
Data normalization: Standardize formats in datasets
Debugging: Mask sensitive data in logs before sharing

The tool offers two modes: plain text for simple replacements, and regex for pattern-based transformations.

How to Use It: Real Examples

Plain Text Replacement

The simplest use case: find an exact string and replace it with something else.

Input:

The Acme Corporation is located in New York.
Acme Corporation announced quarterly results.
Contact Acme Corporation for more information.

Find: Acme Corporation Replace: Acme Inc.

Output:

The Acme Inc. is located in New York.
Acme Inc. announced quarterly results.
Contact Acme Inc. for more information.

All occurrences are replaced instantly. You can preview the changes and copy the result.

Regex Replacement: Replace All Digits

Regex mode unlocks pattern-based replacement. Here's a practical example: masking all digits in a document.

Input:

Order #12345 placed on 2024-03-15
Customer ID: 987654
Amount: $1,234.56

Find (regex): \d+ Replace: #

Output:

Order # placed on ####-##-##
Customer ID: #
Amount: $#,###.##

The regex pattern \d+ matches one or more consecutive digits. Every number is replaced with a single #.

This is useful for creating anonymized test data or redacting sensitive identifiers.

Case-Insensitive Replacement

Input:

apple
Apple
APPLE
ApPlE

Find: apple Replace: orange Mode: Case-insensitive

Output:

orange
orange
orange
orange

Every variant of "apple" is replaced, regardless of capitalization.

Regex with Capture Groups

Capture groups let you rearrange matched text. Replace patterns while keeping parts of the original.

Input:

john.doe@example.com
jane.smith@test.org
admin@company.net

Find (regex): (\w+)\.(\w+)@(\S+) Replace: $2.$1@$3

Output:

doe.john@example.com
smith.jane@test.org
admin@company.net

The regex captures the first name, last name, and domain separately. The replacement swaps the first and last name order using $1, $2, $3 references.

Common Regex Patterns

Pattern	Matches	Use Case
`\d+`	One or more digits	Phone numbers, IDs
`\s+`	Whitespace	Extra spaces
`\bword\b`	Whole word only	Avoid partial matches
`https?://\S+`	URLs	Link replacement
`^.keyword.$`	Lines containing keyword	Filter lines

Options

Case sensitive: Match exact case (default: on)
Whole word: Only match complete words, not substrings
Regex mode: Enable regex pattern matching
Replace all: Replace every occurrence (always on in this tool)

Why Regex Over Plain Text?

Plain text is great for known strings. Regex is powerful for patterns:

Dates: Match MM/DD/YYYY and transform to YYYY-MM-DD
Emails: Extract or normalize email patterns
IDs: Target specific formats like ABC-1234
Cleanup: Remove unwanted characters or formatting

Try It Now

Open the Find and Replace tool and paste your text. Start with plain text for simple replacements, then try regex mode for pattern-based transformations.

Related Tools

Remove Duplicates — Clean up after bulk replacements
Sort Lines — Organize text before or after edits
JSON Formatter — Format and validate JSON after text processing

FAQ

Is regex required to use this tool? No. Plain text mode is the default. Regex mode is an optional toggle for pattern-based replacements.

Does the tool support replacement with newlines? Yes. Use \n in the replacement string to insert line breaks.

Can I replace with nothing (delete matches)? Yes. Leave the replacement field empty to delete all matches.

What happens if the find pattern isn't found? The tool will indicate no matches were found and your input text remains unchanged.

Are there regex limits? The tool uses JavaScript-compatible regex. Complex patterns like recursive matching aren't supported, but most common patterns work fine.