Text Diff & Line-by-Line Comparison Tool
Compare two text files side-by-side or unified. Highlights additions, deletions, and character edits in real time with 100% browser privacy.
Side-by-Side Comparison
🔒 100% Confidential Client-Side Diff
Unlike third-party diff services that store your code snippets on external servers, this comparison algorithm runs purely in your local browser JavaScript engine. Proprietary code, NDA contracts, and private keys remain strictly confidential.
About this tool
How to use it
- Paste your original baseline text into the left box and your updated version into the right box.
- Toggle 'Ignore whitespace' or 'Case sensitive' to filter out superficial differences.
- Inspect the color-coded diff output: green for additions (+), red for deletions (-), and yellow for modified lines (~).
- Review summary metrics for exact counts of added, removed, and identical lines.
Why it matters
Manual proofreading between two revisions of source code or legal documents is notoriously prone to overlooking subtle word alterations or misplaced punctuation. An automated diff tool visually highlights every alteration with zero risk of human oversight.
When to use it
Use this tool to compare Git code changes, review contract clauses before signing, audit configuration file changes, or check edited essays for accidental omissions.
Good to know
All text comparisons are executed strictly in your browser RAM using client-side JavaScript, guaranteeing confidentiality for proprietary source code and confidential contracts.
Common questions
Are my documents or code uploaded to any external server?
No. All diff comparisons execute 100% locally within your browser. No data ever leaves your computer.
What do the +, -, and ~ symbols mean?
'+' indicates a new line added in the modified version; '-' indicates a line deleted from the original; '~' indicates a line that exists in both versions but contains altered text.
Can I compare code with different indentation?
Yes! Checking 'Ignore leading/trailing whitespace' will treat lines with different spaces or tabs as identical if their text content matches.
Can I quickly swap the original and modified sides?
Yes. Click the 'Swap Texts' button to instantaneously invert the left and right inputs and recalculate the diff.