Diff Checker

Paste text in each pane to compare differences side-by-side.

Original
Modified
Loading...

Diff Checker Online - Free Text Comparison Tool

What is this tool and how is it helpful?

This Diff Checker is a free online tool that lets you paste two pieces of text and instantly see the differences between them, highlighted side-by-side — similar to how GitHub shows code changes in a pull request.

With this Diff Checker Online, you can:

  • Compare two versions of code to spot what changed between revisions
  • Review configuration file changes before deploying to production
  • Check document edits to see what was added or removed
  • Debug API responses by comparing expected vs. actual output
  • Validate data transformations by diffing input and output

Whether you're a developer, DevOps engineer, writer, or QA engineer, this tool gives you an instant visual comparison of any two texts.

How to Use the Diff Checker

  1. Paste your original text into the left pane
  2. Paste your modified text into the right pane
  3. Differences are highlighted instantly — red for removed lines, green for added lines
  4. Use Copy Original or Copy Modified to copy either pane's content
  5. Use Clear to reset both panes and start a new comparison

Understanding the Diff Output

The side-by-side view uses standard diff conventions:

  • Red / highlighted lines on the left — lines that exist in the original but not in the modified version (deletions)
  • Green / highlighted lines on the right — lines that exist in the modified version but not in the original (additions)
  • Unmarked lines — lines that are identical in both versions

Common Use Cases

Code Review

Compare a file before and after your changes to do a quick self-review before committing, or to understand what a patch does.

Configuration Management

Diff your config.yaml or .env files across environments to catch accidental differences between staging and production.

Document Editing

Spot changes between two drafts of a document, README, or spec — without needing to track changes in a word processor.

API Debugging

Compare the JSON response you expected with the actual response your server returned to quickly identify discrepancies.

Feedback