Developer Tools

Text Diff Checker

Compare two blocks of text side-by-side to identify added, removed, or modified content instantly.

Diff Mode:
Original Text
Deletions
Modified Text
Additions

Free Text Compare Tool: Find Differences Instantly

A powerful, secure, and fast online Diff Checker. Compare two text files side-by-side to highlight every change, deletion, and addition in seconds.

Why Use an Online Text Diff Checker?

In the digital age, we constantly deal with multiple versions of the same document. Whether you are a programmer debugging code, a writer editing a draft, or a student checking revisions, spotting the subtle differences between two blocks of text can be a nightmare if done manually.

ToolMini's Text Compare Tool automates this process. Instead of straining your eyes to find a missing comma or a changed variable, our tool visually highlights discrepancies using a clear color-coded system. It’s like having a superpower for proofreading.

Our tool runs entirely in your browser using advanced JavaScript libraries. This means your sensitive data—whether it's proprietary code, legal contracts, or personal letters—never leaves your computer. It is the safest way to compare text online.

Key Features of Our Diff Engine

We’ve designed this tool to be robust enough for developers yet simple enough for casual users.

1. Three Comparison Modes

Different tasks require different levels of precision. We offer three distinct modes:

  • Character Mode: The most granular level. It highlights individual letter changes. Perfect for fixing typos or debugging strict data formats (e.g., JSON, CSV).
  • Word Mode: The standard setting. It highlights changed words. Ideal for copywriters, editors, and general document comparison.
  • Line Mode: Compares text line-by-line. Best for comparing large blocks of computer code or structured lists where indentation and line order matter.

2. Visual Color Coding

We use a universal standard for displaying differences:

  • Red (Deletions): Text that exists in the Original version but was removed in the Modified version.
  • Green (Additions): Text that did not exist in the Original but was added to the Modified version.
  • Black/White (Unchanged): Content that is identical in both versions, providing context for the changes.

3. Privacy-First Architecture

Unlike many other free tools that upload your text to a server for processing, ToolMini executes the "Diff" algorithm directly on your device. Your passwords, API keys, or private notes remain 100% confidential.

Common Use Cases

For Developers & Programmers

Quickly compare code snippets without opening a heavy IDE. Check what changed in a function between two git commits, or verify that a minified CSS file matches the source.

For Writers & Editors

Compare a draft submitted by a freelancer with your final edited version to see exactly what changes were made. It’s excellent for generating "Change Logs" for content updates.

For Legal & Business

analyze contract revisions. If a client sends back a signed contract, use this tool to ensure they haven't subtly altered any clauses or terms without tracking changes.

For SEO Specialists

Check for duplicate content or see how a competitor has updated their landing page text over time by comparing cached versions.

How to Compare Two Texts

  1. Paste Original: Copy your older version (Version A) and paste it into the left "Original Text" box.
  2. Paste Modified: Copy your newer version (Version B) and paste it into the right "Modified Text" box.
  3. Select Mode: Choose between "Chars" (for precision), "Words" (context), or "Lines" (structure).
  4. Click Compare: The tool will instantly lock the input boxes and generate a visual report.
  5. Review: Scroll through the result. Use the "Edit Text" button to make corrections and re-compare if needed.

Tips for Accurate Results

  • Clean Your Text: Before comparing, ensure you haven't accidentally pasted extra whitespace or HTML tags unless you intend to check those.
  • Use Line Mode for Code: If comparing Python, JavaScript, or PHP, "Line Mode" usually gives the most readable results as it respects code structure.
  • Check for Hidden Characters: Sometimes texts look identical but differ due to invisible characters (like Tab vs. 4 Spaces). Our "Char Mode" will reveal these.

Frequently Asked Questions (FAQ)

Yes, ToolMini's Text Compare tool is completely free to use. There are no daily limits, hidden costs, or sign-up requirements.

Your privacy is our priority. This tool processes all data locally in your browser using JavaScript. No text is ever uploaded to our servers or stored in any database.

Absolutely. It works great for languages like HTML, CSS, JavaScript, PHP, Python, and Java. We recommend using Line Mode for checking code to maintain readability.

  • Chars: Highlights every single differing letter or symbol.
  • Words: Highlights changed words (treats specific words as units).
  • Lines: Highlights entire lines if any part of the line has changed.

Currently, this is a text-based tool. You need to open your file (Word, PDF, Notepad), copy the contents, and paste them into the input boxes.

There is no hard limit set by us, but extremely large texts (e.g., millions of characters) might slow down your browser since the processing happens on your device. It works smoothly for standard documents and code files.

This is a read-only comparison tool ("Diff Checker"). It highlights differences but does not offer features to merge changes or resolve conflicts like Git.

If you have the source text and the suspect text, yes. You can paste them side-by-side to see exactly how much content was copied directly versus rewritten.

No, the comparison is case-sensitive. "Hello" and "hello" will be marked as a difference. This is crucial for coding and precise document proofing.

Yes! Our responsive design works on smartphones and tablets. However, for complex side-by-side comparison, using a desktop or laptop screen is recommended for the best experience.

Red highlights text that was present in the Original version but has been deleted or changed in the Modified version.

Green highlights text that is new. It appears in the Modified version but was not present in the Original version.

Character mode compares every single letter. If you differ by even one space, it might flag huge chunks of text as different. Try switching to Word Mode for a cleaner view of standard text documents.

Yes, but because minified code is usually on a single line, you should use **Char Mode** or **Word Mode**. **Line Mode** will simply show the entire file as one changed block if a single character is different.

Yes! Paste two lists (like emails or inventory items) and use Line Mode. The tool will quickly identify which items are missing or added between the two lists.