Text Diff Checker
Paste two versions of a text — original and edited — to instantly see which lines were added, removed, or changed between them.
How to Use This Tool
Paste the original text
In the left box — the "before" version.
Paste the edited text
In the right box — the "after" version.
Click "Compare texts"
See exactly which lines were added, removed or unchanged.
Review the highlighted differences
Green for added, red for removed, no highlight for unchanged.
About the Text Diff Checker
Comparing two versions of a document by eye is slow and error-prone, especially for anything longer than a few sentences — a single word change buried in a large paragraph is easy to miss when scanning manually side by side.
This tool performs a line-by-line comparison between two blocks of text, identifying which lines exist in both versions unchanged, which lines were removed (present in the original but not the edited version), and which lines were added (present in the edited version but not the original).
This kind of comparison is commonly used for reviewing document revisions, comparing two drafts of content, checking what changed between two versions of code or configuration, or verifying an edit only touched the parts of a document it was supposed to.
Frequently Asked Questions
Does this compare word-by-word, or only line-by-line?
This tool compares line by line — if a single word changes within a line, the entire line is marked as changed (shown as a removed line plus an added line) rather than highlighting just the specific word that differs.
What does it mean if a line shows as both removed and added?
This typically means the line's content changed slightly — the old version of that line is shown as removed (in red) and the new version is shown as added (in green), even though conceptually it's really one line being edited rather than a completely different line being inserted.
Does the order of lines matter for the comparison?
Yes — this is a straightforward line-position comparison rather than a smart re-ordering detector, so if you moved a block of text to a different position without changing its content, it may show as removed from its old position and added at its new position.
Can I compare two large documents, or just short text?
There's no strict length limit, though very large documents (thousands of lines) may take a moment longer to process and the resulting diff output can become long and harder to scan visually.
Is this the same as a code diff tool like Git?
It uses a similar line-comparison concept, but this is a simplified, general-purpose text tool rather than a full version-control diff engine — it's well suited to comparing prose, lists, or simple text documents rather than complex code with nested logic.
Is my text uploaded to a server to perform the comparison?
No — the entire comparison happens locally in your browser using JavaScript. Neither text is ever uploaded or stored anywhere.