Text Compare

About Text Compare

Text Compare is a free online tool that shows you exactly what changed between two pieces of text. Paste your original text on the left and the modified version on the right, then click Compare. Every added line is highlighted in green, every removed line in red, and changed lines in yellow with word-level highlights so you can pinpoint the exact words that differ.

This text comparison tool is useful for comparing document revisions, proofreading edits, reviewing configuration file changes, checking code differences, comparing data exports, and spotting changes in any kind of content.

The tool uses the longest common subsequence (LCS) algorithm — the same approach used by Git and Unix diff — to produce the most accurate, minimal set of changes. Word-level diff is enabled by default so modified lines show precisely which words changed, not just which lines.

Everything runs locally in your browser. Your text is never uploaded or stored on any server.

Text Compare Features

• Runs entirely in your browser

  Text Compare processes everything client-side — nothing you paste, type, or upload is sent to a server.

• Free, instant, no sign-up

  No account, no usage limits, no paywall. Results update as you type or click.

• Side-by-side diff — spot every addition, deletion, and change

  Text Compare is a free online tool that shows you exactly what changed between two pieces of text. Paste your original text on the left and the modified version on the right, then click Compare. Every added line is highlighted in green, every removed line in red, and changed lines in yellow with word-level highlights so you can pinpoint the exact words that differ.

How to Use Text Compare

1. 1

   Paste the original text in the left panel.

2. 2

   Paste the modified or updated text in the right panel.

3. 3

   Click Compare — differences are highlighted instantly.

4. 4

   Green highlights show added text, red shows removed text, yellow shows modified lines with word-level changes pinpointed.

Examples

Original: The tenant shall pay rent by the 1st of each month.

Revised: The tenant shall pay rent by the 5th of each month.

Line changed — word-level highlight: "1st" → "5th"

Original: function add(a, b) { return a + b; }

Revised: function add(a, b) { return a + b + 0; }

Line changed — word-level highlight: added "+ 0"

Original: The project was completed on time and under budget.

Revised: The project was completed ahead of schedule and under budget.

Line changed — word-level highlight: "on time" → "ahead of schedule"

Original: timeout=30
debug=false

Revised: timeout=60
debug=false

Line changed — word-level highlight: "30" → "60"

Original: 3 years of experience in marketing.

Revised: 5 years of experience in digital marketing.

Line changed — word-level highlight: "3" → "5", added "digital"

Practical Uses for Text Compare

• Review what changed between two drafts of a contract
• Compare two versions of a config file before deploying
• Proofread an edited article against the original draft
• Compare two CSV exports to spot changed values
• Check what changed between two versions of a resume
• Compare two code snippets to review a refactor

Who Uses the Text Compare Tool

• Developers compare two versions of code or config files to review exactly what changed.
• Editors and writers proofread revisions by comparing an edited draft against the original.
• Legal and contract teams review redlines by comparing two versions of a contract or policy document.
• Data analysts compare two data exports to spot which values changed between snapshots.
• Students compare drafts of an essay to track revisions before submission.

Comparisons

Frequently Asked Questions

What is a text compare tool?

A text compare tool (also called a diff checker) takes two pieces of text and highlights exactly what changed between them — which lines were added, removed, or modified. It saves you from manually reading both versions to spot differences.

Does it compare word by word or line by line?

Both. The tool first compares line by line to find which lines changed, then within each changed line it highlights the exact words that differ. You can switch between Word diff and Line diff modes using the toggle in the results toolbar.

Can I use this to compare code?

Yes — paste code from any language into the two panels and differences are highlighted immediately. The monospace font and line-by-line comparison make it easy to review code changes.

What algorithm does the text comparison use?

The longest common subsequence (LCS) algorithm, which is the same approach used by Git, GitHub, and Unix diff. It finds the minimal set of changes needed to transform one text into the other.

Can I compare two versions of a document?

Yes — paste the old version on the left and the new version on the right to see every change highlighted. This works for any text content: articles, emails, contracts, config files, and more.

Is there a size limit?

No hard limit. The tool handles large texts in your browser, though very large files (100,000+ lines) may slow down the comparison.

Can I compare two versions of a contract?

Yes — paste the original contract on the left and the revised version on the right. Every added, removed, or changed clause is highlighted, making it easy to review a redline without reading both documents line by line.

Can I compare two CSV exports to find changed values?

Yes — paste each export's rows into the two panels. Line-level differences are highlighted, and changed rows show word-level highlights pinpointing exactly which field changed.

Does formatting like bold or italics affect the comparison?

No — the comparison works on plain text content only. Formatting differences that don't change the actual text won't be detected, since only the text itself is compared.

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