Text Diff Checker
Compare two blocks of text line by line or word by word and highlight what was added or removed. Free, private, in your browser.
See what changed between two texts
Paste the original text on the left and the changed text on the right, then hit Compare. Additions are highlighted in green, removals in red, and unchanged text stays plain. Switch the granularity between Line — which compares whole lines and suits lists, configs and code — and Word, which flows the text inline and pinpoints exactly which words changed within a sentence. Two checkboxes relax the match: Ignore case treats letters the same regardless of capitalization, and Ignore whitespace ignores spacing differences entirely.
Under the hood it runs a longest-common-subsequence diff over tokens — lines for Line mode, or words and the whitespace runs between them for Word mode — so it finds the smallest set of additions and removals. The ignore options only normalize the text used for matching; the highlighted result always shows your original characters, so reindented code compared with Ignore whitespace still displays its real spacing. Everything runs locally in your browser — nothing is uploaded.
Frequently asked questions
When should I use Word mode instead of Line mode?
Line mode compares whole lines, so changing a single word marks the entire line as removed and re-added — ideal for code, configs and lists where the line is the unit. Word mode diffs token by token and highlights just the words that changed inside a line, which reads far better for prose, sentences and edited paragraphs.
Do the Ignore case and Ignore whitespace options change my text?
No. They only affect how tokens are matched: Ignore case compares letters regardless of capitalization, and Ignore whitespace strips spacing before comparing, so reformatted or reindented text stops showing up as changes. The highlighted output still shows your original characters exactly as you pasted them.
Why do I get 'inputs are too large to compare'?
The diff builds a comparison table whose size is the number of tokens on each side multiplied together, and very large inputs are rejected to keep the tab from freezing. Word mode creates many more tokens than Line mode, so switching to Line mode or comparing shorter sections usually resolves it.