Bulk Replace with Regex and Tidy Up Text
When prepping logs or CSVs, rewrite recurring patterns all at once. Bulk-replace with regex, then deduplicate and sort lines to finalize the layout. Everything runs in your browser and your data is never uploaded.
Why This Takes Longer Than It Should
Reordering CSV columns, pulling out log lines matching a pattern, normalizing inconsistent address formats — an editor's find-and-replace handles these one at a time, but conditional replacement across thousands of lines needs regular expressions. The hard part is verification: you want to see what a pattern will hit before it hits it.
What's Actually At Risk Here
- ✓What you're replacing is usually real data — a customer list, a log file. Pasting it into an online regex tool hands it over verbatim.
- ✓Processing stays in the browser, so a CSV containing personal data is fine to work with directly.
- ✓It runs offline, which covers work environments where outbound traffic is blocked.
2 Steps to Get It Done
Click any tool name below to go directly to that tool.
- 1Regex Replace
Use regex to replace all matching occurrences with another string
- 2Line Tools
Deduplicate and sort the resulting lines to clean up the output
Where People Get Tripped Up
These catch people out even when the steps are followed correctly. Skimming them first saves a redo.
- Replacement isn't undoable. Save a copy of the source data first.
- Greedy patterns like `.*` match past where you intended. Confirm the matches before running the replacement.
- When CSV values contain commas or newlines, regex alone tends to break down. For large jobs, use a real parser.
Frequently Asked Questions
- Can I use capture groups (like $1)?
- Yes. Capture group references like $1 and $& (the whole match) are supported. Preview the result on screen to confirm the pattern behaves as intended.
- Is it safe to process large amounts of text?
- All processing happens in your browser, so the text you edit is never sent externally — even logs with sensitive content can be tidied safely.
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