Online text comparator

How to read the result

The comparison shows a simple line-by-line diff. Two leading spaces mark a line present in both texts, - marks content removed from the original, and + marks content added in the modified version.

  Tools in a Tab
- Local processing
+ Processing in your browser
  No account required

The summary counts unchanged, deleted and added lines. Swapping the texts reverses the comparison: additions become deletions and vice versa.

Comparison rules

• The unit is a complete line, not a word or character.
• Capital letters, accents, tabs and spaces are significant.
• CRLF and CR line endings are normalized to LF, so the comparison does not report differences caused only by those line-ending conventions.
• A trailing newline creates an additional empty line and is therefore reported as a difference.
• You can compare text against an empty input. Two empty inputs are rejected because they do not produce a useful comparison.

The algorithm searches for a common subsequence of lines to present insertions and deletions in a stable order. Repeated lines can produce more than one valid alignment; the algorithm chooses one deterministically.

Common uses

• Review quick changes to configurations or code snippets.
• Compare an answer before and after transforming it.
• Detect spaces or line breaks that alter a hash.
• Prepare a readable explanation before reviewing changes in version control.

For JSON documents, the JSON formatter can normalize indentation before comparison. To check for byte-level differences that this text comparison may normalize, also calculate SHA-256 for the original files.

What it doesn’t do

This version does not highlight individual words, ignore whitespace, apply language-specific rules or merge three versions. It does not read files; paste the text into each input. It is not a substitute for a Git review, which also provides history, authorship and project context.

Protection limits

Each side accepts up to 200,000 characters. The number of lines on the left multiplied by the number on the right must not exceed 1,000,000: the comparison needs memory proportional to that product. If you reach the limit, compare the document in smaller sections.

Privacy

Both texts and the result stay in this tab. They are not sent for processing, stored persistently or added to URL parameters. Closing or reloading the page clears the comparison.

Frequently asked questions

Can you ignore whitespace?

Not in this version. Whitespace-sensitive comparison avoids hiding changes that can affect a configuration, signature or hash.

Why does a trailing newline count as a difference?

The comparison treats a trailing newline as an additional empty line. Some tools and formats also distinguish text with and without a final newline.

Can it compare binary files?

No. It compares pasted text and does not read binary files.