Text Diff Checker Online
Compare two texts side by side and see the differences highlighted. Free online diff tool with ignore case, trim, and empty line options.
Features
- ✓Line-by-line comparison of two texts
- ✓Color-coded diff output (green for additions, red for removals)
- ✓Ignore case differences option
- ✓Trim whitespace for cleaner comparisons
- ✓Skip empty lines to focus on content changes
- ✓Summary showing added, removed, and unchanged line counts
How to Use
- 1Paste the original text in the left panel
- 2Paste the modified text in the right panel
- 3Toggle options like ignore case, trim whitespace, or skip empty lines
- 4The diff result appears below with color-coded highlights
- 5Review the summary for a quick overview of changes
Examples
Input
Original: Hello World Modified: Hello Earth
Output
- Hello World + Hello Earth
Input
Original: Line 1\nLine 2 Modified: Line 1\nLine 1.5\nLine 2
Output
Line 1 + Line 1.5 Line 2
Input
Original: A\nB\nC Modified: A\nC
Output
A - B C
Input
Original: foo\nbar\nbaz Modified: foo\nqux\nbaz\nnew
Output
foo - bar + qux baz + new
How to Compare Texts and Find Differences
Comparing two pieces of text to find the differences is one of the most common tasks in software development, writing, and data analysis. This tool performs a line-by-line diff — the same fundamental algorithm used by Git, GitHub, and professional code review tools — right in your browser.
The diff algorithm works by finding the Longest Common Subsequence (LCS) between the two texts. Lines that appear in both texts are marked as unchanged. Lines present only in the original are marked as removed (shown in red), and lines present only in the modified version are marked as added (shown in green).
The "ignore case" option treats uppercase and lowercase letters as identical for comparison. This is useful when comparing configuration files, SQL queries, or any text where casing may have changed but the content is semantically the same.
The "trim whitespace" option strips leading and trailing spaces from each line before comparison. This catches differences caused by inconsistent indentation or trailing spaces — a common source of false positives in manual comparisons. The "skip empty lines" option removes blank lines from both texts before comparing.
All processing happens locally in your browser using client-side JavaScript. Your texts are never sent to any server, making this tool safe for comparing sensitive content like configuration files, credentials, contracts, or private notes.