🔍 Diff Checker
Compare two text blocks side by side. Instantly see what was added, removed, or changed.
About This Diff Checker
What It Does
The Diff Checker compares two blocks of text line by line and highlights what was added, removed, or changed. Paste your original text on the left and the modified version on the right, then click Compare to see a color-coded breakdown. Green lines are additions, red lines are removals, and yellow lines are modifications. A summary at the top tells you at a glance how many lines changed in each category.
Features
- Side-by-side text comparison
- Color-coded output: green for added, red for removed, yellow for changed
- Line numbers on every row with change sign indicators (+, -, ~)
- Summary stats showing added, removed, changed, and unchanged line counts
- Swap button to quickly reverse the comparison direction
- 100% client-side — your text stays in your browser
Common Use Cases
Developers use this tool to compare code versions when they don't have access to git diff, spot differences between configuration files across environments, review edited documentation for unintended changes, compare log output before and after a change, and verify that a copy-paste of sensitive data didn't introduce errors. Writers use it to compare drafts and see what was edited. System administrators compare server configs between staging and production.
Tips
The diff is line-based, so it works best on structured text like code, configs, and formatted documents. For prose or paragraphs with soft line wrapping, the comparison may show entire rewrapped paragraphs as changed — consider hard-wrapping your text first. Use the Swap button to flip which side is treated as the original if you paste them in the wrong order. The tool works well for files up to about 1,000 lines — beyond that, browser performance may slow down.
FAQ
How is this different from git diff?
Git diff uses sophisticated algorithms (Myers, histogram) to find the minimal set of changes. This tool does a simpler line-by-line comparison. It's great for quick visual checks but won't detect moved blocks of code the way git diff --color-moved does.
Does it work with non-text content?
It compares the raw text of whatever you paste. Binary content won't display meaningfully, but you can compare base64-encoded strings, hex dumps, or any text representation of binary data.
Can I compare entire files?
Yes — open the file in any text editor, copy its contents, and paste into the left and right panels. For very large files (over 10,000 lines), consider using a desktop diff tool or the command line instead.
What happens when the line counts don't match?
The diff checker handles mismatched line counts gracefully. Extra lines on one side show as additions or removals. The line numbers continue through both sides, so you can see exactly where content diverges.