Text Diff Checker
Compare two blocks of text side-by-side and highlight every addition, deletion, and change.
What is a Text Diff Checker?
A diff checker compares two pieces of text and highlights exactly what has changed between them. "Diff" is shorthand for "difference" — the concept comes from software development, where developers routinely compare versions of code to track what changed between revisions. But text diffing is useful for anyone who works with documents, contracts, articles, or any written content.
This tool supports three diff modes: Word Diff highlights individual changed words (most readable for prose), Line Diff shows which entire lines were added or removed (useful for code and structured content), and Character Diff pinpoints changes at the single character level (best for finding subtle edits like typos or punctuation changes).
When to Use a Text Diff Checker
Document Revision
Compare two versions of a contract, report, or article to see exactly what was changed — helpful for proofreading edits, tracking revisions, and version control without dedicated software.
Code Review
Quickly spot the differences between two snippets of code, configuration files, or command outputs when you don't have a full git setup handy.
Plagiarism & Copying
See how closely two pieces of text match, or identify what has been changed in a text that may have been copied and lightly edited from another source.
Email & Template Drafts
Compare different drafts of an important email or template to confirm which changes were made before sending the final version.
Your text never leaves your browser. Nothing is sent to any server.
Results appear immediately — word, line, or character level in milliseconds.
See a summary of how many words or lines were added, removed, or kept the same.
No limits on text length. No account required. Free forever.
Need Version Control for Documents?
For ongoing document collaboration with tracked changes, comments, and version history, dedicated tools make working in teams much smoother.
Frequently Asked Questions
Is there a limit on how much text I can compare?
There's no hard limit. The tool runs entirely in your browser, so very long texts (tens of thousands of words) will process fine — it may just take a second longer on slower devices. For most documents, comparisons complete in milliseconds.
What does "Ignore case" mean?
When "Ignore case" is checked, differences in capitalisation are not flagged. So "Hello" and "hello" would be considered the same. Useful when comparing text where capitalisation changes are intentional or irrelevant to what you're checking.
Which diff mode should I use?
Use Word Diff for general prose comparison — it's easiest to read. Use Line Diff for code, CSV, or structured data where line-level changes matter most. Use Character Diff when you need to catch very small changes like a single letter being swapped, a punctuation mark added, or a subtle spelling difference.
Can I compare code files?
Yes — paste any code directly into the input boxes. For code, Line Diff mode usually gives the clearest results, matching how tools like Git show differences in source files.
Frequently Asked Questions
What does a diff checker do?
A diff checker compares two pieces of text and highlights every difference between them — additions shown in green, deletions in red, and unchanged text in normal colour. It is useful for comparing document versions, reviewing code changes, or checking what changed between two pieces of text.
Can I compare code as well as plain text?
Yes — paste any text including code. The comparison is purely textual, so it works equally well for code, prose, configuration files, or any other text content.
Does it compare word by word or character by character?
You can choose — line-by-line comparison shows which entire lines changed, word-level comparison highlights individual word differences within lines, and character-level shows every individual character change. Line-by-line is best for code; word-level is best for prose.
Can I export the diff result?
You can copy the diff output as plain text. A visual diff with colour coding can be copied as HTML for use in documents or web pages.
Is my text uploaded to a server?
No. All comparison happens in your browser. Your text never leaves your device.