Why replace a whole list at once?
Word, Google Docs and most editors replace one word at a time. That is fine for a single typo, but slow when a product is renamed, a client changes its company name, or a document has to switch from British to American spelling. You open the Replace box, type the old word, type the new one, press Replace All, and do it again for the next pair. With twenty pairs it is easy to miss one, or to replace a word inside another word by accident.
This tool takes the whole list in one go. Put each pair on its own line, paste your text, and every pair is replaced in a single pass. The result shows each change highlighted, and the table on the right counts how many times each pair was used, so a pair that matched nothing stands out straight away.
When it is useful
- Renaming: a product, a project, a company or a person's job title across a long document.
- Spelling: British to American English (or the other way), or your team's preferred terms.
- Glossaries: replace jargon with plain words before sending a report to a client.
- Hiding names: replace real names with "Client A", "Staff B" before you share an example. For emails, phone numbers and card numbers, the AI Privacy Mask finds them automatically.
- Files: subtitles (
.srt), CSV files, web pages and code. Open the file, replace, and download it with the same format.
How to use it
- Paste your text in box 1, or press Open a text file.
- Write the pairs in box 2, one per line:
old → new. You can also type->or=>instead of the arrow, or paste two columns copied from Excel or Google Sheets. - Check the result in box 3. Replaced text is highlighted; hover over it to see what it was. Deleted text is shown crossed out.
- Press Copy result or Download as file.
To delete a word, leave the right side empty: very →. To match a line break or a tab, write \n or \t. Lines that start with # are notes and are skipped.
The options
| Option | What it does | Example |
|---|---|---|
| Whole words only (on) | Only replaces the word when it stands on its own. | cat → dog leaves "category" alone |
| Match case (off) | Only replaces text with exactly the same capitals. | Apple → Pear skips "apple" |
| Keep capitals (on) | When case is ignored, the new word follows the capitals of the text it replaces. | "FALCON" becomes "OSPREY", "falcon" becomes "osprey" |
| Regular expressions (off) | For advanced users: the left side is a JavaScript regular expression, and $1 on the right inserts a captured group. | (\d+)kg → $1 kg |
Three things it does that one-by-one replacing gets wrong
- All pairs at the same time. With
Monday → FridayandFriday → Monday, the two days swap. Replacing one by one would turn both into Monday. - Longer phrases first. With
Project Falcon → Project OspreyandFalcon → Osprey, the longer phrase is matched first, whatever order you type them in. - No replacing inside a replacement. New text is never searched again, so
a → abcannot run away.
Saving and sharing a word list
Type a name and press Save list to keep the list in this browser for next time. To share it with a colleague, copy the box, or keep it as a two-column sheet in Excel and open it here with Open a word list. Swap old and new turns the list around, which is handy for undoing a change.
How this tool was tested
Before publishing, I ran 86 automated checks on the publish version of this page, in a Chromium-based browser (the engine behind Chrome and Edge) at phone width, 375 px. Last full run: 25 October 2026.
- 28 checks on the word list and the replacing. These include whole words ("category" stays when cat becomes dog), capitals, accented letters, Chinese text, symbols like
$5and[x], swapping two words, longer phrases first, and deleting. - 8 checks on regular expressions, including
$1, back-references and invalid patterns. - 12 checks on files: CSV word lists with quotes and commas, subtitle files keeping Windows line endings, CSV files keeping the mark Excel needs for accents and Chinese, and the 5 MB limit.
- 38 checks on the page: buttons, saved lists, about 1 MB of text with 53 pairs (finished well under the 1.5-second limit), the language switch and the layout.
What the tests do not cover: I did not test in Firefox or Safari, and the files were test files I made, not real documents. If a pair does not work the way you expect, send me the text and the list on the Contact page.
FAQ
Is my text uploaded anywhere?
No. The replacing runs as a small script in this page, and opened files are read by your browser only. Word lists you save are kept in this browser's local storage, not on a server.
Can it change a Word (.docx) or Excel file directly?
No, it works on plain text, so bold, colours and tables are not kept. For a formatted Word document, copy the text out, or use Word's own Replace for the few words that need formatting. CSV files, subtitles and other text files work fine.
How do I replace something that starts or ends with a space?
Put it in double quotes, for example " ," → ",". Without quotes, spaces at the start and end of each side are ignored.
Does "whole words only" work with Chinese and Japanese?
Chinese and Japanese are written without spaces, so there is no clear word edge. For pairs that start or end with Chinese or Japanese characters, the tool replaces the text wherever it appears. Mixed pairs such as "FALCON" inside Chinese text still use whole-word matching.
Is there a size limit?
Files up to 5 MB can be opened. Very long texts work, but the highlighted preview only shows the first 100,000 characters; copying and downloading always use the full result.