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Line-by-Line Text and Code Diff Checker

Compare original and changed versions, receive a deterministic summary and text-only unified diff without uploading data or applying a patch.

  • Line-level diff
  • Up to 5,000 lines per side
  • No patch application
Online tool

Try the tool

Add your data, choose the settings, and get the result.

Input

The comparison is line-based, normalizes CRLF/CR to LF, and never applies the generated patch.

Result

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Your data stays here

Text and selected files are processed in the current browser and are not sent to a server to produce the result.

Reviewed: 2026-07-17
01

How to use it

  1. 1

    Paste the original text into the first field.

  2. 2

    Paste the changed version and optionally enable trailing-whitespace ignoring.

  3. 3

    Run the comparison, review the summary, and copy the diff.

02

What the tool can do

  • Deterministic line comparison with additions, deletions, and replacement groups.
  • CRLF and CR normalization to LF before comparison.
  • Optional ignoring of spaces and tabs only at the end of each line.
03

Common use cases

  • Reviewing configuration changes before approval.
  • Comparing two versions of a text API response.
  • Finding added and removed lines in a small code fragment.
04

How it works inside

The algorithm uses a bounded LCS matrix and a fixed tie-breaker for reproducible output.

The unified diff contains one bounded hunk for the full entered text and is rendered as plain text.

05

Questions and answers

Can the tool apply the generated patch?

No. It only produces a text representation of differences and changes no files or repositories.

Why can a large comparison be rejected?

Fixed character, line, and operation limits prevent the tab from stalling on unsafe input sizes.