Text Diff Checker

Text Diff Checker — Compare Two Texts Online

Compare two blocks of text, code, or JSON side by side and see every difference highlighted instantly with this free online diff checker. Added lines, removed lines, and changes light up in color, so you can spot exactly what changed between two versions of a file, config, contract, or API response in seconds.

It is the quick alternative to setting up git diff for ad-hoc comparisons: paste two versions of anything — SQL schemas, environment files, meeting notes, generated output — and get a precise line-by-line comparison. Everything runs locally in your browser, so confidential documents are never uploaded.

How to Compare Two Texts Online

Paste the original

Put the first version of your text or code into the left pane.
Paste the changed version

Put the second version into the right pane.
Review the diff

Added lines are highlighted in green and removed lines in red, aligned side by side for easy scanning.
Iterate as needed

Edit either side and the comparison updates — perfect for verifying a fix or merge by hand.

Features of the Diff Checker

Side-by-side comparison

Both versions aligned line by line, with additions and deletions color-coded.
Works for any text

Code, JSON, SQL, config files, prose, translations — if it is text, it diffs.
Instant results

Differences compute in real time as you paste or edit, with no submit step.
Completely private

Contracts, credentials, and proprietary code are compared in-browser and never transmitted.
No length anxiety

Compare long files and logs without upload limits.

Frequently Asked Questions

How do I compare two text files online?

Open both files, copy the contents into the left and right panes of this tool, and every added, removed, or changed line is highlighted immediately — no installation or signup needed.

Is this diff tool safe for confidential documents?

Yes. The comparison algorithm runs entirely in your browser. Neither side of the diff is uploaded, stored, or logged anywhere.

Can I diff JSON or code with this tool?

Absolutely — it is text-based, so JSON, YAML, SQL, JavaScript, or any source code compares cleanly. Tip: format both JSON documents first so the line-by-line diff is meaningful.

What do the colors in the diff mean?

Green marks lines that were added in the new version, red marks lines that were removed from the original, and unchanged lines stay neutral so real changes stand out.

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Text Diff Checker