Text & JSON Diff Checker

How to compare

1. Choose Text or JSON mode.
2. Paste the "before" and "after" content into the two boxes.
3. Click "Compare" to see how many lines or entries were added, removed, changed or left unchanged, with the full diff below.
4. Use "Swap" to flip the two sides, and "Copy diff summary" to copy a compact summary of the differences.

How the text diff works

Text is compared line by line; line-ending style alone (LF, CRLF or CR) never counts as a difference. A run of removed and added lines is paired up and shown as changed lines, and within each pair only the characters that actually changed are highlighted — the common prefix and suffix are left plain. For very long lines (over 20,000 characters) the inline highlight is skipped and the whole line is shown as changed.

Comparison works per character (code point), so emoji and non-ASCII text are never split apart.

JSON comparison rules

• Object keys are compared without regard to order.
• Arrays are compared index by index, so reordering elements shows up as changes at each position — element moves are not detected.
• Differences are reported with paths such as $.user.name or $.items[0].
• A value that changes type — for example from a number to a string — is reported as "Type changed", distinct from a plain value change.
• Below the structural diff you also get a line-by-line diff of both documents with their keys sorted, so nothing hides in formatting differences.

Syntax errors are reported with the exact line and column plus a hint for common mistakes such as trailing commas. Nesting deeper than 20 levels is compared as a whole, and differences beyond 200 entries are omitted — both cases are clearly flagged.

Input limits

Each side of a text comparison accepts up to 200,000 characters and 2,000 lines. Inputs beyond the limit are not compared; you get an error message instead. For large files, pasting only the sections that likely changed is the fastest way to review them.

Privacy

Comparisons run entirely in your browser. Your texts, JSON documents and the diff results are never sent to a server, so you can safely paste configuration files or data that contain sensitive information.

FAQ