Text Diff Checker
Compare two texts side by side and see the differences highlighted.
What Is a Text Diff Checker?
A text diff checker compares two pieces of text and highlights the differences between them. Added text is shown in green, removed text in red, and unchanged text in the default color. This is the same concept behind git diff and code review tools, applied to any text.
How Do I Compare Two Texts Online?
Paste the original text in the left panel and the modified text in the right panel. Click Compare and the tool highlights every difference: additions, deletions, and changes. The side-by-side view makes it easy to spot even small differences in large documents.
When Do I Need a Diff Checker?
Use it to compare document versions before and after editing, verify that copy-paste operations preserved all text, check configuration file changes, review contract revisions, compare code snippets, and verify translation completeness. Any time you need to know exactly what changed between two versions of text, a diff checker is the fastest way.
Can This Tool Handle Large Documents?
Yes. The diff algorithm runs efficiently in your browser and handles documents of several thousand lines without noticeable delay. For extremely large files (100,000+ lines), performance depends on your device capabilities. All processing is done locally — neither text is uploaded to any server.
What Algorithm Does This Diff Tool Use?
The tool uses a variation of the longest common subsequence (LCS) algorithm, which is the same fundamental approach used by Unix diff and git diff. It finds the longest sequence of lines common to both texts, then identifies lines that were added, removed, or changed relative to that common sequence. This produces minimal, readable diffs.
How Do I Compare Code Versions Without Git?
Paste the old version of your code in the left panel and the new version in the right panel. The diff tool highlights every change, making it easy to review modifications without a version control system. This is especially useful for comparing code snippets from Stack Overflow, reviewing changes in configuration files, or comparing output from two different runs of a script.