JustilityBatch find & replace
Apply ordered literal or regular-expression replacement rules, preview changes and download the updated text.
Processed on your device. Your files are never uploaded by Justility.
How privacy worksHow it works
Paste text or open a UTF-8 file, enter find and replacement rules in the desired order, and choose literal or regex matching. Apply replacements, check per-rule counts and the updated preview, then copy or download the complete text.
Supported formats
UTF-8 text up to 1 MB; one to 20 rules, find values up to 2,000 characters and replacements up to 10,000 characters. Output up to 5 MB; preview up to 100,000 characters.
Good to know
Rules run sequentially and replace all matches. Regex uses JavaScript Unicode mode and a 2.5-second worker limit. Each rule permits up to 100,000 matches. Text is not saved automatically, and source files are unchanged.
Worked example
Before
Hello Ada, your order OLD-42 is ready. Rules: Hello → Hi; OLD- → NEW-.
After
Hi Ada, your order NEW-42 is ready. Rule 1: 1 replacement; rule 2: 1 replacement.
A later rule sees earlier replacements. Move rules up to change their order before applying them.
Preview cascading replacements
Literal mode treats punctuation and dollar signs literally. Regex mode supports capture replacements such as $1, $&, and $<name>. Use multiline anchors for line-specific replacements. An empty replacement removes matches; an empty find value is rejected.
Regex testerTroubleshooting
Why did a later find-and-replace rule change newly inserted text?
Every rule operates on the previous output. Reorder the rules or use a more specific expression. Resetting or editing a rule clears the previous result so it cannot be downloaded by mistake.
Common questions
Can a regex freeze the page?
Regex runs in a dedicated worker which is terminated after its time limit or cancellation. Simplify an expensive expression or process less text if it times out.
Can I use this without an internet connection?
Yes, after you prepare this tool from Offline help and the browser retains its assets. Installation is optional. All processing dependencies are bundled locally.