Home › Files & Data tools › CSV Find & Replace CSV Find & Replace Run a find-and-replace across an entire CSV — all columns or just one — with optional case-sensitive and regex modes.
Quick answer: Run a find-and-replace across an entire CSV — all columns or just one — with optional case-sensitive and regex modes.
Last updated 2026-05-01
Frequently asked questions How do I run find-and-replace on a single CSV column? Pick the column from the 'Scope' dropdown. Only that column is rewritten; the rest of the row passes through untouched. Does it support regular expressions? Yes. Toggle 'Use regular expression' to switch from literal text matching to JavaScript-flavour regex. Useful for things like `\bcustomer-(\d+)` → `cust_$1`. Are matches case-sensitive? By default no — `Ada` and `ada` both match. Toggle 'Case-sensitive' on for an exact-case match. How many replacements does the tool report? The footer shows the total number of replacements applied across all rows and columns in the chosen scope. Useful for sanity-checking before downloading. Will my CSV be uploaded? No. Find & Replace runs entirely in your browser using Papaparse — your data never reaches our server. Will quoted fields with commas survive the replace? Yes. The parser is RFC-4180 compliant, so quoting is preserved through the round-trip. Can I replace newlines or tabs inside cells? Yes, but only via regex — type `\n` or `\t` in the Find box with regex mode on. Literal mode treats your input as plain text. What if my regex is invalid? An error appears below the controls explaining what's wrong, and the preview falls back to the original rows so you don't accidentally download a broken file. How do I use a backreference in the replacement? Standard JavaScript syntax: `$1`, `$2`, etc. Example: Find = `^(\d+)/(\d+)/(\d+)
CSV Find & Replace — Free Online Tool | Toolbox4Free
, Replace = `$3-$2-$1` re-orders a date column from `MM/DD/YYYY` to `YYYY-DD-MM`."}},{"@type":"Question","name":"Can I undo the replace?","acceptedAnswer":{"@type":"Answer","text":"There's no undo — but the source CSV is untouched (only the download is rewritten), so just re-run with new settings."}}]}
, Replace = `$3-$2-$1` re-orders a date column from `MM/DD/YYYY` to `YYYY-DD-MM`. Can I undo the replace? There's no undo — but the source CSV is untouched (only the download is rewritten), so just re-run with new settings.