Text Diff Checker
Compare two blocks of text and see exactly what changed, line by line.
Paste text into both boxes to see a line-by-line diff. Added lines are tinted green, removed lines red.
About this tool
A text diff checker compares two blocks of text and shows exactly what changed between them. Developers use it to review edits, writers use it to track revisions between drafts, and anyone can use it to spot the difference between two versions of a document, configuration, or message. This tool diffs your text line by line the moment you paste it.
Under the hood it computes the longest common subsequence of the two line sets, then walks that sequence to mark each line as unchanged, added, or removed. Added lines are prefixed with a plus and tinted green, removed lines are prefixed with a minus and tinted red, and a running summary tells you how many lines were added and removed.
Everything runs locally in your browser — your text is never uploaded, logged, or stored. That makes it safe for comparing confidential documents, contract drafts, code snippets, or any content you would rather not paste into a server-side service.
Examples
Input
Original: a, b, c → Changed: a, x, c
Output
Line 2 removed "b", added "x"; lines 1 and 3 unchanged
A single changed line shows as one removed line and one added line.
Input
Original: hello → Changed: hello\nworld
Output
"hello" unchanged; "world" added (+1 added, 0 removed)
Input
Original: keep\ndrop → Changed: keep
Output
"keep" unchanged; "drop" removed (0 added, 1 removed)
Common uses
- Developers reviewing edits between two versions of a config or code snippet
- Writers tracking changes between drafts of an article or essay
- Editors comparing a contract or document before and after revisions
- Support teams diffing log output or error messages to spot what changed
- Translators checking which lines changed in source copy before re-translating
- Anyone comparing two pasted lists to see what was added or removed
Frequently asked questions
Is this text diff checker free?
Yes. It is completely free with no sign-up, no limits, and no watermarks.
Does my text get uploaded anywhere?
No. The comparison runs entirely in your browser using JavaScript. Your text never leaves your device.
How does the diff work?
It splits both inputs into lines, computes their longest common subsequence, then marks each line as unchanged, added, or removed in reading order.
Does it compare line by line or character by character?
It compares line by line. Each line is treated as a whole, so any change within a line shows that line as one removed and one added.
Does it handle different newline styles?
Yes. It normalizes Windows (\r\n), classic Mac (\r), and Unix (\n) line endings before comparing.
Embed this tool
Free to use on your own site. It stays fast and private for your visitors.
<iframe src="https://hypercho.com/embed/text-diff-checker" title="Text Diff Checker by Hypercho" width="100%" height="560" style="border:1px solid #d8cec3;border-radius:16px;max-width:720px" loading="lazy"></iframe>
<p style="font:13px sans-serif"><a href="https://hypercho.com/tools/text-diff-checker" target="_blank" rel="noopener">Text Diff Checker</a> by <a href="https://hypercho.com" target="_blank" rel="noopener">Hypercho</a></p>Related tools
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