How can I compare two texts online?

Paste the first version into "Original text" and the second into "Modified text", then run the tool. You get the number of lines added and removed plus a unified diff showing exactly what changed — free, no signup, all in your browser.

What is a diff checker used for?

A diff checker compares two versions of a text and highlights what was added, removed, or changed. Writers use it to review edits, developers to compare config files or snippets, and students to check revisions against an original draft.

How do I find the differences between two texts?

Use the diff checker above: paste both texts and read the unified diff output. Lines prefixed with + exist only in the modified text, lines prefixed with - exist only in the original, and unprefixed lines are unchanged context around the edits.

What is the best way to compare two text files online?

Paste the contents of both files into the two boxes and run the checker — the line counts tell you how much changed and the unified diff shows where. The comparison is line-based, so it works best when each change is on its own line.

Is there a free online diff tool?

Yes — this text diff checker is free with no signup and no limits on this page. Paste any two texts, get added/removed line counts and a unified diff instantly, with nothing uploaded to a server.

Text Diff Checker — Compare Two Texts Online

What is Text diff checker?

Text Diff Checker — Compare two texts online with this free text diff checker — see lines added and removed plus a unified diff. Runs in your browser; nothing is uploaded.

Line-based diffing only — the comparison works line by line, not word by word. The vendored diff2html engine (rtfpessoa/diff2html, MIT) parses a unified diff computed by its bundled jsdiff diff library (also vendored, MIT) into structured file blocks; the wrapper counts lines typed "insert" as added and "delete" as removed, and shows the unified diff text itself. All computation happens in your browser; nothing is uploaded. Limitation: moved or reordered lines appear as a removal plus an addition, not as a move.

Why use this text diff checker?

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Built for text diff checker

Compare two texts online with this free text diff checker — see lines added and removed plus a unified diff. Runs in your browser; nothing is uploaded.

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Transparent & honest

The comparison is line-based: a single changed word marks its whole line as removed and re-added.

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Private by design

Everything runs in your browser. Your inputs never leave your device.

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Works everywhere

Fully responsive — perfect on desktop, tablet, and mobile. No app needed.

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Regularly updated

Regularly maintained and reviewed to ensure accuracy.

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Free forever

No accounts, no limits, no watermarks. Use Text Diff Checker as much as you need.

How to use Text Diff Checker

1Paste the first version of your text into the "Original text" box.
2Paste the second version into the "Modified text" box.
3Run the tool to compute the line-by-line difference.
4Read "Lines added" and "Lines removed" for the change counts.
5Read the "Unified diff" output: lines starting with + were added, lines starting with - were removed, and unchanged context lines start with a space.

What can you do with Text Diff Checker?

Compare two texts online — Compare two texts online with this free text diff checker — see lines added and removed plus a unified diff.
What is diff checker used for — Compare two texts online with this free text diff checker — see lines added and removed plus a unified diff.
Find differences between two texts — Compare two texts online with this free text diff checker — see lines added and removed plus a unified diff.
Free online diff tool — Compare two texts online with this free text diff checker — see lines added and removed plus a unified diff.

Good to know

The comparison is line-based: a single changed word marks its whole line as removed and re-added.
Moved or reordered content shows as a removal plus an addition, not as a move.
Both texts are compared exactly as pasted, including whitespace and line endings — trailing spaces can produce "changes" that look identical.

How it works

Line-based diffing only — the comparison works line by line, not word by word. The vendored diff2html engine (rtfpessoa/diff2html, MIT) parses a unified diff computed by its bundled jsdiff diff library (also vendored, MIT) into structured file blocks; the wrapper counts lines typed "insert" as added and "delete" as removed, and shows the unified diff text itself. All computation happens in your browser; nothing is uploaded. Limitation: moved or reordered lines appear as a removal plus an addition, not as a move.

Examples

One word changed

Status: ok — 1 line added, 1 line removed; the unified diff shows the word swap on one line.

Line added

Status: ok — 1 line added, 0 removed; the new line appears with a + prefix in the unified diff.

Identical texts

Status: ok — 0 added, 0 removed; the texts are identical.

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