Text Diff Checker

Compare two blocks of text and highlight exactly what changed, line by line.

Word counts, case conversion, de-duplicating a list, cleaning up text copied out of a PDF — the kind of editing work that doesn't need a full word processor, just a tool that does one thing correctly. These run in your browser too, so there's nothing to upload and nothing kept afterward.

Like the rest of the Text tools, the Text Diff Checker runs as plain JavaScript in your browser tab. What you type or paste in is never sent anywhere — there's no server round-trip for it to go through.

There's no right moment to reach for the Text Diff Checker — some people run it once before shipping something, others keep it open and use it every day. Either way, it stays free, there's no limit on repeat use beyond a light rate limit, and nothing about a previous run is remembered the next time you open the page. It's also one of several tools in the Text category here, so if it turns out not to be quite the right one, the related tools listed below are worth a look before searching elsewhere.

Common questions

Is my text uploaded anywhere? No — like the rest of the text tools, this one runs locally in your browser and never sends your text anywhere.

Is there a length limit? No hard limit, though very long input (tens of thousands of words) will naturally take a moment longer to process.

Does it work on mobile? Yes — it's a plain web page, so it works the same in a phone or tablet browser as it does on a desktop.

Related Text tools

A few other text tools people tend to reach for alongside the Text Diff Checker:

• Word Counter
• Case Converter
• Duplicate Checker
• Text Cleaner