About the Diff Checker (Text/Code Comparison)
A diff checker compares two versions of text or code and highlights exactly what was added, removed, or changed between them — the same underlying concept used by Git and code review tools, made available as a simple, instant, standalone tool. This is invaluable whenever you need to compare two documents, configuration files, or code snippets without setting up version control.
This tool is useful for developers comparing two versions of a config file or code snippet outside of Git, writers and editors comparing draft revisions, and students comparing their answer against a reference solution to spot exact differences quickly.
To use it, paste your original text into the left box and the changed version into the right box, then click "Compare." The tool highlights removed lines/words in red and added lines/words in green, with unchanged text shown normally, letting you scan a large document and immediately spot every difference rather than reading line by line yourself. You can switch between line-level and word-level comparison depending on whether you're comparing whole paragraphs or fine-grained text edits.
For example, comparing two versions of a paragraph where only one sentence was reworded will show the old sentence struck through in red and the new sentence highlighted in green, while every other unchanged sentence appears in plain text — making it obvious that only that one specific change occurred, even inside a long document.
A common mistake is comparing text with different line endings or trailing whitespace, which can make the diff show far more "changes" than actually happened content-wise; this tool normalizes trivial whitespace differences by default so you can focus on meaningful changes, with an option to disable that normalization if exact whitespace differences matter for your use case (such as reviewing code formatting).
Tip: use word-level diffing when comparing prose or documentation where small wording tweaks matter, and line-level diffing when comparing code or structured configuration files where entire lines are typically added or removed together — switching between the two modes based on your content type gives you the clearest, most useful comparison for each specific situation.