Text Diff Viewer

Supports text, code, and configuration file comparison with side-by-side and unified view modes. Highlights additions, deletions, and changes line by line, supports synchronized scrolling and one-click swap, suitable for code review, document proofreading, and configuration verification.

Usage Instructions

🚀 Quick Start

Paste the original text on the left (code, documents, configs welcome)
Paste the modified text on the right
Click “Compare”; once computed, the fullscreen result opens automatically
In fullscreen, check the Summary at the top, then use the colors to locate added/removed lines
Markers & line numbers: 🟢 Added (-:N) / 🔴 Removed (N:-) / Gray = context

📌 Common Scenarios

Code review: verify the scope and impact of changes before committing, and use the diff as context for review comments
Document proofreading: compare revisions to spot added/removed paragraphs and wording changes
Config changes: diff environment or config files before and after edits to avoid accidental parameter removals
Log analysis: compare logs before and after an incident to pinpoint key differences
API responses: compare JSON/text responses across versions to confirm field and order changes
Merge conflicts: inspect both sides of a conflict manually to understand what should be kept or discarded
Release notes: use the diff as raw material to summarize changes for changelogs
Translation updates: check how source text changes impact translations to avoid missing updates

🎛️ Comparison Parameters & View

Use the gear menu to toggle “Sync scroll” (side‑by‑side only); unified view is unaffected

🧭 Usage Advice

“Swap” flips both sides so it’s easier to inspect older revisions
For large edits, compare in sections to keep the diff readable
When whitespace and line breaks matter, first normalize them with the Text Formatter tool, then come back here to compare
Long texts may take a few seconds—watch the progress hint and give it time
“Clear” only clears the text and doesn’t affect settings; toggle “Sync scroll” from Settings (side‑by‑side)

⚠️ Limitations & Compatibility

Line-based view: tiny character changes highlight the entire line
Whitespace counts—different indentation shows as changes
Different line endings (CRLF/LF) count as changes; normalize them first
Very long inputs take longer; if the browser slows down, split the diff
Mobile screens are cramped; desktop offers a fuller view

🔒 Privacy & Security

All processing happens in your browser; data never leaves your device

❓ FAQ

Why does it say the texts are identical?

Every character matches. If you expected changes, check for hidden spaces or line breaks

Can whitespace or line-ending changes be ignored?

Not automatically—please normalize formatting before comparing

How do I export the diff?

Click the Export icon in fullscreen to save a single‑page HTML; open it to print or share

The progress hint keeps spinning. Is it stuck?

Large diffs can take a few seconds. If nothing appears after 30 seconds, refresh and compare in smaller chunks