Diff Result
Enter text in both fields to see the differences
How to Compare Text Online
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Paste or Upload Your Texts
Enter or upload the original text into the left panel and the modified version into the right panel. You can paste directly, drag and drop files, or use the upload button to load .txt, .json, .md, .html, .css, .js, and other text-based files. - 2
Choose Your Comparison Mode
Select whether to compare by characters, words, or lines. Character mode catches every tiny edit. Word mode is ideal for document revisions. Line mode works best for code reviews and structured content where changes happen line by line. - 3
Adjust Options and View Results
Toggle options like Ignore Case or Ignore Whitespace to filter out formatting noise. Switch between Side by Side view for parallel comparison or Inline view for a unified diff. Additions appear in green and deletions in red. - 4
Export or Copy the Diff
Once you have identified all differences, copy the result to your clipboard or download the diff output. Use the statistics panel to get a quick summary of how many segments were added, removed, or left unchanged.
Common Use Cases
Code Reviews and Pull Requests
Document and Contract Revisions
Configuration and Data File Audits
Content Editing and Proofreading
Why use a Diff Checker?
The Diff Checker is a free browser-based tool that compares two blocks of text and highlights every difference between them. Whether you are reviewing code changes, auditing configuration files, or tracking edits in a document, this tool gives you a clear, color-coded view of additions, deletions, and unchanged content. All processing runs entirely in your browser, so your data never leaves your device.
Unlike basic text comparison, this diff tool supports three granularity levels: character, word, and line comparison. Character mode is perfect for spotting single-letter typos or subtle punctuation changes. Word mode treats each word as an atomic unit, making it ideal for document revisions where sentences are rephrased. Line mode mirrors how tools like Git display diffs, which is the standard for code formatting and software development workflows. You can also pair it with the JSON Comparer for structured data or the SQL Formatter to clean up queries before comparing them.
Advanced options let you ignore case differences and normalize whitespace, so you can filter out formatting noise and focus on meaningful content changes. The side-by-side and inline view modes give you flexibility in how you read the results. For developers, the tool handles file uploads for formats like .js, .ts, .json, .xml, .css, .html, and .md. Writers and editors can use it alongside the Word Counter to track both content changes and document length, or the Readability Calculator to ensure edits improve clarity.
How It Compares
Most online diff tools either require you to create an account, limit the number of comparisons per day, or process your text on a remote server. The FindUtils Diff Checker is completely free with no signup required, no usage limits, and no server-side processing. Your text stays in your browser at all times, which makes it safe for comparing sensitive code, confidential contracts, or proprietary configuration files.
Compared to desktop tools like WinMerge or Beyond Compare, this online diff checker requires zero installation and works on any device with a browser. It supports the same core comparison modes, plus the convenience of instant access. For developers who need structured comparisons, the JSON Comparer and JSON Diff tools offer specialized support for nested data formats.