Diff Checker
Compare two blocks of text — additions and deletions highlighted instantly.
A free online diff checker — paste the original and changed text, compare line by line or word by word. No signup, runs entirely in your browser.
Diff
Paste text into both boxes to see the diff.
What does a diff checker do?
A diff checker compares two versions of the same text and highlights exactly what changed — lines or words that were added, removed, or left untouched. It's the same logic behind git diff, code review tools, and document comparison features, applied to any pasted text.
Line diff vs word diff
Line diff treats each line as a single unit — if anything on a line changes, the whole line shows as removed and its replacement as added. This is standard for code and config files. Word diff instead breaks lines into individual words, so a single changed word inside a long sentence shows up as just that word, not the entire line — much easier to read for prose.
Reading the output
Text highlighted in red with a strikethrough was in the Original but removed. Text highlighted in green was added in the Changed version. Plain text with no highlight appeared in both and is unchanged.
Common uses
Comparing two drafts of a document, reviewing a config file change before deploying it, checking what an AI rewrite actually changed, or spotting the difference between two versions of a legal clause or contract.
Frequently asked questions
Related tools: JSON Formatter · Case Converter · HTML to Markdown
