Text Diff Checker

Compare two blocks of text line by line to spot differences quickly.

Original Text

Updated Text

Diff Output

No comparison yet.

How to Use This Text Diff Checker

Paste the original text on the left and the updated text on the right, then click Compare Text. Matching lines are shown unmarked, removed lines are prefixed with -, and added lines are prefixed with +, similar to a standard code diff.

How the Comparison Works

This is a line-by-line comparison: it checks line 1 against line 1, line 2 against line 2, and so on by position, rather than intelligently detecting that a block of lines simply moved. That means inserting or deleting a single line near the top of a long text can make every line after it show as changed, even if the actual wording didn't change — for best results, compare texts that are already reasonably aligned.

When a Line-Level Diff Isn't Enough

Rewording a single word in the middle of a long sentence shows up here as the entire line being removed and re-added, since comparison never looks inside a line to isolate what actually changed. That's a reasonable trade-off for quick checks on short text, config snippets, or a paragraph of prose, but it's not what you want for reviewing code changes or long documents — tools built for that, like Git's diff, use algorithms designed to detect moved blocks and highlight the specific words that changed within a line, rather than treating a line as one indivisible unit.

FAQ

Does this highlight word-level changes within a line?

No, comparison happens at the line level — a line with even a single character changed is shown as fully removed and fully re-added.

Why do all my lines show as different when I only changed one?

If a line was inserted or deleted rather than edited in place, every following line shifts position, and since comparison is positional, that shift can cascade down the rest of the text.

Does whitespace affect the comparison?

Yes, lines are compared exactly as typed, so a trailing space or different indentation will register as a difference.

Is this the same kind of diff that Git or GitHub shows?

No. Git uses a more sophisticated algorithm that can detect moved blocks of text and often highlights the specific words that changed within a line. This tool does a simpler positional, line-by-line comparison, which is fine for quick checks on shorter text but isn't a substitute for a version-control diff on a large or heavily restructured document.