Find and Replace

How Find and Replace works

Replace words or patterns across large text with regular expression support, match case and whole word options. Everything happens inside this page: the tool reads your input, runs the calculation or conversion locally, and hands the result back to you. Nothing is transmitted, because there is no backend to transmit it to.

That design choice is deliberate. Most free tool sites upload your files to a server, process them there, and quietly keep a copy. Toolcin cannot do that — the site is a set of static files. If your connection dropped the moment the page finished loading, every tool would still work.

Plain text or regular expression

With regex off, the search is a literal substring match — fast, predictable, and what most edits need. With regex on, the find field becomes a pattern, so \d+ matches any run of digits and (\w+)@(\w+) captures parts of an email.

Match case and whole word are separate switches: whole word stops “cat” from matching inside “category”, which is the single most common reason a replace damages a document.

What gets replaced

Every occurrence is replaced, not just the first — the tool does not stop after one match. That is usually what people want and occasionally what they did not: replacing “is” with “was” across a page changes “this” into “thwas” unless whole word is on.

Working safely

Copy the original somewhere before a broad replace; there is no undo history beyond the browser's own. For a document where structure matters, run the text diff tool afterwards to see exactly what changed.

Good to know

• Works offline once loaded, including on flights and in locked-down networks.
• No file size limit beyond your device's own memory.
• Free to use, with no account and no usage counter.
• Results are produced locally, so they are not logged or shared with anyone.

Questions