What's the difference between Smart, Word, and Char diff precision?

Smart and Char highlight differences at the character level for tight, exact pills; Word groups the highlight by whole words, which reads more naturally for prose and sentences.

Can I ignore whitespace-only or line-ending changes?

Yes. "Hide whitespace changes" ignores differences that are only spacing, and "Normalize line breaks (CRLF/LF)" treats Windows and Unix line endings as equivalent so they don't show up as changes.

Can I export or share the diff?

Yes. "Export" downloads a standard unified .diff file, and "Share" compresses both texts into the URL hash so you can send a link that reproduces the same comparison for anyone who opens it.

Does it support formats other than plain text?

Yes. Choose a syntax (JSON, JavaScript/TypeScript, HTML/XML, CSS, SQL, Python, YAML, Plain Text) for editor highlighting, and use "Format JSON both inputs" to pretty-print JSON before comparing.

Is my text uploaded to a server?

No. Diffing, formatting, and history are all computed and stored locally in your browser; nothing is uploaded, including when you generate a share link.

Diff Checker & Code Comparator: Check Diff Side-by-Side

Real-time editor

Hide whitespace changes

Hide unchanged lines

Disable line wrap

Ignore

Case insensitive diff Normalize line breaks (CRLF/LF)

Transform text

No diffs saved yet. Click "Save" in the top bar to store diffs.

⊖ 0 removals 13 lines

⊕ 5 additions 16 lines

Original text

Open file

Changed text

Open file

Private by architecture: All processing is 100% client-side memory. Your data never leaves this browser tab.

About This Tool

Diff Checker compares two blocks of text, code, JSON, or YAML side-by-side (or unified), highlighting changes down to the character or word level in real time as you type. It covers everyday comparison work: config changes, API response diffs, two versions of a file.

For JSON specifically, it diffs text as-is, paste it through "Format JSON both inputs" first if you want a clean structural comparison instead of noise from different indentation, or use JSON Formatter to pretty-print each side beforehand.

Key Features

Explain summary: a local, non-AI breakdown listing each added/removed/modified line plus change counts, computed entirely in-browser.
Saved diff history: up to 30 diffs persist in localStorage; reopen or clear them from the sidebar's History tab.
Transform text shortcuts: format JSON on both sides, trim whitespace on both sides, or sort lines alphabetically, right from the sidebar.
Overview minimap: a dual-track rail showing where changes fall in the document; click to jump straight there.
Focused-review toggles: hide unchanged lines, hide whitespace-only changes, or disable line wrap.
Swap controls: flip which side is "original" for either the stats header or the input panes.

Example

Original text:

{
  "name": "yourstand",
  "version": "1.0.0",
  "license": "MIT"
}

Changed text:

{
  "name": "yourstand",
  "version": "1.1.0",
  "private": true
}

Click "Find difference" to get a side-by-side view with "version": "1.0.0" and "license": "MIT" struck through in red, and "version": "1.1.0" and "private": true highlighted in green, plus a removals/additions count at the top.

FAQ

What's the difference between Smart, Word, and Char diff precision?: Smart and Char highlight differences at the character level for tight, exact pills; Word groups the highlight by whole words, which reads more naturally for prose and sentences.
Can I ignore whitespace-only or line-ending changes?: Yes. "Hide whitespace changes" ignores differences that are only spacing, and "Normalize line breaks (CRLF/LF)" treats Windows and Unix line endings as equivalent so they don't show up as changes.
Can I export or share the diff?: Yes. "Export" downloads a standard unified .diff file, and "Share" compresses both texts into the URL hash so you can send a link that reproduces the same comparison for anyone who opens it.
Does it support formats other than plain text?: Yes. Choose a syntax (JSON, JavaScript/TypeScript, HTML/XML, CSS, SQL, Python, YAML, Plain Text) for editor highlighting, and use "Format JSON both inputs" to pretty-print JSON before comparing.
Is my text uploaded to a server?: No. Diffing, formatting, and history are all computed and stored locally in your browser. Nothing is uploaded, including when you generate a share link.