Online Text Diff Checker
Compare two blocks of text side-by-side. Instantly highlight additions, deletions, and modifications at the line, word, or character level.
Text Compare
How to use Text Compare
- Lines Mode: Best for code or comparing lists. Highlights changes line by line.
- Words Mode: Good for text documents. Highlights changed words within sentences.
- Chars Mode: Detailed character-by-character comparison.
- JSON Mode: Formats and compares JSON objects structurally.
Granular Change Tracking
Whether you are reviewing source code, legal documents, or JSON payloads, our tool visualizes exactly what changed.
Side-by-Side View
Provides the classic developer interface. Left pane for the original text, right pane for the revised text, with perfectly aligned line numbers.
JSON Awareness
Enable JSON formatting before comparing to logically restructure minified payloads and clearly identify missing object keys or mutated values.
Zero Privacy Risks
Execute complex diffing algorithms exclusively within your local browser. Paste API keys, proprietary code, or PII securely without network transmission.
Who Uses Text Comparators?
Software Engineers
Validate code changes outside your IDE, compare environment files (.env) securely, and debug misaligned API responses instantly.
Writers & Editors
Determine exactly what a client or proofreader changed in a manuscript when they fail to use "Track Changes" in their word processor.
Frequently Asked Questions
What does line vs character comparison mean?
Line comparison treats each row as a unit and highlights the whole row if any part changed — ideal for code. Character comparison highlights the exact letters and punctuation that changed inside a paragraph — better for essays and prose editing.
Can I compare formatted vs minified JSON?
Yes — comparing a minified JSON string against a formatted one would normally flag everything due to whitespace. Use the JSON comparison mode to parse and normalize both sides first, so only real data differences are highlighted.
Is my text uploaded anywhere?
No. Both texts are diffed entirely in your browser — nothing is sent to a server, so it's safe to compare contracts, code, or private drafts.
Is there a size limit on the texts?
Only your device's memory. Documents of tens of thousands of lines diff quickly in a modern browser; very large files may be slower but will still complete.
Can this tell me what percentage of two texts is identical?
The diff highlights insertions and deletions rather than giving a similarity score. For a quick sense of overlap, the amount of unhighlighted text is your visual answer — most of the page unhighlighted means the texts are largely identical.
Related Data Tools
About This Utility
This tool is provided completely free of charge by Mavertex. Built by Kumar (an independent UI developer), our platform ensures your privacy by executing all operations strictly within your local browser DOM.
We prioritize zero-trust architecture. No files or inputs are ever uploaded to remote servers. This page serves as both an interactive web application and an educational resource explaining the mechanics of client-side operations. For further details on transparency and third-party network usage (including AdSense), please review our Privacy Policy.