1
Add both versions
Put the old text on the left and the new text on the right. Paste directly or read common text and code files.
TEXT.02 TEXT DIFF
Online Text Diff
Enter original and revised text side by side to highlight removals and additions directly in each editor, with synchronized scrolling for continuous review.
Original text
Revised text
§ 01
Choose useful granularity before reviewing the changes
2
Choose comparison
Words suit prose, characters suit exact proofreading, and lines suit code, configuration, and logs. Ignore case or whitespace when appropriate.
3
Review in place
Removals are highlighted in red on the left and additions in green on the right. Scrolling or resizing either editor keeps the other one synchronized.
§ 02
Text diff turns visual searching into a shortest edit path
A diff algorithm finds additions and removals that transform the old sequence into the new one. Unchanged content stays neutral, removals are red, and additions are green, exposing punctuation, values, or whole-line changes.
Word view suits prose, character view finds fine spacing, punctuation, and number changes, and line view resembles Git and code review. Filters affect only the comparison and never rewrite either input.
§ 03
What each granularity solves
Granularity
Best for
Characteristic
Word
Articles, contracts, product copy
Natural reading with changes grouped by word
Character
Exact proofreading, short strings, data
Exposes punctuation, spaces, and individual characters
Line
Code, configuration, logs, lists
Preserves structure for side-by-side alignment
§ 04
File reading and comparison stay in the browser
Files are opened with FileReader and JavaScript computes the diff in the page. Text is neither sent to a server nor written to history or browser storage.
For huge files, binary formats, or full merge-conflict workflows, a desktop diff app and version control remain better. This page focuses on fast, one-off text review.
§ 05
Frequently Asked Questions
Q1Is my text uploaded?
No. Pasting, file reading, and comparison all happen in the current browser page without saved history.
Q2When should I use word, character, or line diff?
Use words for natural language, characters for exact string or value proofreading, and lines for code, configuration, and logs.
Q3Does ignoring whitespace modify the input?
No. It only treats whitespace as equivalent during comparison; both editor values remain unchanged.
Q4Does it support CJK text and emoji?
Yes. Comparison uses Unicode strings, and character mode segments user-perceived characters to handle CJK and most emoji sequences.
Q5Why do both editors scroll together?
Synchronized scrolling keeps nearby content aligned. Progress is mapped proportionally, so texts of different lengths can still reach the end together.