Text Compare / Diff Checker

See what changed between two drafts, messages or code files. Compare locally, explore each edit, and keep a report.

Private browser processingWord & line modesTXT, JSON & HTML reports

1. Add your two versions

0 text units · 0 lines

0 text units · 0 lines

Up to 100,000 UTF-16 text units and 3,000 lines per version. Open UTF-8 files up to 400 KB. You can compare against an empty version.

2. Choose what matters

Line endings (CRLF / CR) are normalized to LF. Spaces and tabs can be ignored; line breaks still matter. Words mode includes punctuation and spacing tokens.

Paste text or try the example to begin.

Using Text Compare / Diff Checker

Review revisions to writing, messages or code without uploading the text. Word mode highlights small edits; Line mode highlights complete changed lines.

  1. Paste the original and revised versions, open UTF-8 files or try the example. An empty version lets you see everything added or removed.
  2. Choose Word or Line mode. Optionally ignore letter case or spaces and tabs, then compare. Enable Compare as I type only if you want automatic updates.
  3. Navigate change blocks, inspect both versions and copy a report or download TXT, JSON or standalone HTML. Open the HTML report to print it from your browser.

Example

Original: The launch is scheduled for Friday.
Revised: The launch is scheduled for Monday.
Word mode highlights Friday as removed and Monday as added.

Questions & answers

Is my text uploaded or saved?

No. Comparison runs in a local browser worker using locally hosted scripts. Drafts and results are not saved to browser storage. Downloaded reports contain both versions; Clear both removes the current drafts and results.

What is the difference between Word and Line mode?

Word mode compares tokens consisting of words, punctuation and spacing, rather than editorial word counts. Line mode compares complete lines. Added and removed token counts can therefore include punctuation, spaces and line breaks in Word mode.

What do the ignore options do?

Ignore letter case uses Unicode lowercase comparison without changing the displayed drafts. Ignore spaces and tabs disregards those characters for matching; line breaks and other whitespace still matter. Texts can match under these options while their displayed formatting remains different.

Why are line endings normalized?

Windows CRLF and older CR line endings are converted to LF before comparison. LF and CRLF alone are not treated as content changes. Final line breaks remain meaningful and changed line breaks are shown with a visible arrow marker.

Can I compare code or a PDF?

Compare plain text or text-based code files; code is never executed. PDF and Word documents need to be exported to plain text first. This tool does not interpret programming syntax, detect plagiarism or judge meaning.

What are the size limits?

Each editor supports 100000 UTF-16 text units and 3000 lines. File opening supports UTF-8 text up to 400 KB. Each tokenized version is limited to 12000 comparison tokens, with at most 2000 token edits and 1000 change blocks. Very different texts may need Line mode or smaller sections. The worker stops after eight seconds.

What is in the reports?

TXT includes both normalized drafts and the changed sections. JSON includes the drafts, options and structured segments. HTML preserves highlighted original and revised versions, contains no executable scripts and can be printed. Reports describe changes; they are not patches to apply to a file.

Guides for this tool

Examples and checks to help with your next step.

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