How it works
- Paste, type, or open both versions from your device.
- Choose the precision and cleanup options that fit your content.
- Review additions and removals side-by-side or as a unified diff.
Useful features
- Smart, line, word, and character-level comparison
- Side-by-side and unified diff views
- Whitespace, case, and blank-line controls
- Local file opening, drag and drop, copy, and .diff download
Common uses
- Editors checking revisions without tracked changes
- Developers reviewing logs, configuration, or documentation
- Operations teams spotting changes in reports and records
Tips for a cleaner comparison
- Ignore whitespace when indentation is not meaningful.
- Use word or character precision for short prose edits.
- Turn off line wrapping when reviewing long log or code lines.
How to compare two texts online
Place the original text on the left and the revised text on the right. Select Compare—or keep Live comparison enabled—to make the diff checker mark deleted content in red and added content in green.
Choose line precision for rewritten paragraphs, word precision for normal editing, or character precision when punctuation and small spelling changes matter. Side-by-side view preserves context, while unified view creates a compact change history.
Compare two text files online
Open or drag one text-based file into each editor to compare them without first copying their contents. Common source, configuration, log, CSV, and plain-text files up to 5 MB are read locally by your browser.
ComparLab compares the readable text inside each file. It does not extract content from binary Word, PDF, or spreadsheet documents, so paste the relevant text or columns from those formats instead.
What the text diff checker can ignore
Formatting noise can hide the changes you actually need to review. Use the whitespace, letter-case, and blank-line options when those differences are not meaningful for your task.
- Whitespace-only edits in copied or reformatted text
- Capitalization changes when letter case is unimportant
- Empty lines added during document formatting
Related comparison tools
Frequently asked questions
How do I check the difference between two texts?＋
Paste the original text on the left and the changed text on the right, then select Compare. Added content appears in green and removed content in red.
Is this online diff checker free?＋
Yes. ComparLab works without registration or payment.
What happens to the text I compare?＋
Comparison content is held in memory and processed locally in your browser. It is not uploaded to a ComparLab server or sent to analytics.
Can I compare text files?＋
Yes. Open or drag common text-based files up to 5 MB. The browser reads them locally.
Can I ignore whitespace and letter case?＋
Yes. Both options are available beneath the editors, along with blank-line and wrapping controls.
What is the difference between the views?＋
Side-by-side aligns both versions in two panels. Unified view places unchanged, removed, and added lines in one Git-style stream.
Can I compare source code?＋
Yes. Use Code Compare or the dedicated SQL, Java, and YAML tools for language-specific examples and guidance.
Is there a file size limit?＋
This version applies a 5 MB per-file safety limit and pauses live comparison above 500,000 combined characters to protect browser responsiveness.
More comparison tools are coming
PDF, Word, Excel, and image comparison are planned for a future release. They are not part of this version, and there are no inactive buttons pretending otherwise.