Text Diff Checker | Dogu Sangja

How to use

Paste the original text and the changed text into the two boxes and the comparison appears — there’s no button to press, and the result keeps updating as you edit. Removed content is shown with a strikethrough and a red background, added content with an underline and a green background, and in line mode each line also gets a leading + (added) or − (removed) mark so the change is still clear even without relying on color.

Compare by line, word or character

Line: best for code, config files or lists, where a line is the meaningful unit. Any change inside a line marks the whole line as changed.
Word: highlights exactly which words changed inside a sentence. Useful for reviewing edited prose or a translation, where you want to see what actually moved.
Character: for catching very small differences such as typos, spacing or punctuation marks.

All three modes compare the same two texts at a different zoom level, and you can switch between them at any time with the buttons above the boxes.

Whitespace and case options

By default, whitespace and case differences both count as changes. Turn on ignore whitespace to skip extra spaces at the start or end of a line or differences in the amount of space between words. Turn on ignore case to treat uppercase and lowercase letters as the same. This is handy for comparing text that went through auto-formatting or a case cleanup, so only the real content changes remain visible.

Reading the result

On a wide desktop screen, the original and changed text are shown side by side, each with its own removals or additions marked. On a narrow phone screen, the two texts are combined into a single stream instead — both views show the same comparison, just laid out differently. The summary above the result shows the number of additions, removals and unchanged units, counted in whichever unit (line, word or character) you currently have selected.

Privacy

Both texts are compared entirely inside this browser. Nothing is saved or sent anywhere, and everything disappears when you close the page.

Frequently asked questions

When should I compare by line, word or character?

Line mode is easiest to read for code, config files or lists, where a line is the natural unit. Word mode is better when only a few words changed inside a sentence, such as edited prose or a translation review — it points straight at what actually changed. Character mode is for spotting tiny differences like typos, spacing or punctuation.

What do "ignore whitespace" and "ignore case" actually change?

Ignore whitespace stops leading/trailing spaces on a line, or differences in how much space is between words, from being counted as a change. Ignore case treats "Hello" and "hello" as the same text. You can turn both on at once, which is useful for isolating real content changes from text that only went through auto-formatting or a case cleanup.

Can it handle very long texts?

The comparison runs entirely in your browser, so very large or very different texts can take a moment. You'll see a note when the input is large, and if the comparison would take too long, the tool skips the detailed comparison and shows the whole text as replaced instead of freezing the page.

What's the difference between the side-by-side and unified views?

On a wide screen, the original and changed text are shown in two columns so you can see removals and additions separately. On a narrow phone screen, two columns become hard to read, so the tool instead shows one combined stream with removals and additions in the order they occur.

Text Diff CheckerBeta

Side by side

Unified