How to Compare Two Texts Online and Find Every Difference

A counterparty sends over a contract with "a couple of minor edits" — the document runs 14 pages, and finding those edits by eye is hopeless. Or you spent a week writing an article, saved three versions, and forgot which one was final. Sound familiar? That's exactly what text comparison is for — and it requires nothing to install.

When it saves the day

• a lawyer sent back an edited contract — you need to see exactly what they changed;
• a copywriter delivered the text and you want to check that old paragraphs didn't get lifted from another source unchanged;
• two config files or two lists — you need to find the discrepancies;
• you forgot which edit you made to the latest version of an email or an article.

How it works

Open the text comparison tool and paste the two versions into the left and right panes. The service splits both texts and highlights the differences: what was added, what was removed, and where. All the computation happens in your browser, so you can compare even confidential documents — the text never leaves your computer.

There are two comparison modes, and the difference matters. By lines is the classic diff: it shows which lines disappeared and which appeared. It's great for code, lists, and configs. By words is more "human": it catches an edit inside a sentence even when the line itself stayed the same. For contracts and articles, word mode is what you need.

Common traps

1. Invisible characters. A non-breaking space or a different quote mark looks identical but counts as a different character. If the tool reports "no differences" and you know perfectly well there are some, inspect the text with the whitespace visualizer.
2. Line endings. Text from Windows and text from Linux can differ by invisible line breaks — those phantom "changes" at the end of every line are exactly this.
3. Comparing from memory. Don't paste text from your head — copy both versions from the files in full, headings and signatures included.