Using the Diff Checker to Compare Text Files

When to Use a Diff Checker

• Compare config files before and after an edit
• Review what changed between two API responses
• Spot differences in minified JS or CSS
• Check that a copy/paste did not introduce whitespace changes

Step 1: Open the Tool

Go to /tools/diff-checker. You will see two side-by-side text areas.

Step 2: Paste Your Content

• Left panel: original (old) version
• Right panel: modified (new) version

Step 3: Read the Output

The diff view highlights:

• Green lines: added in the new version
• Red lines: removed from the original
• White lines: unchanged

Inline mode shows character-level changes within a line.

Step 4: Copy the Diff

Click Copy as Unified Diff to get a standard patch format suitable for sharing or applying with git apply or patch.

Tips

• Use the Ignore Whitespace option to skip indentation-only changes
• Use Ignore Case for case-insensitive comparisons