Syntax reading
Highlighting improves readability but the source is never executed.
Compare code online.
Review code side by side with line numbers, language-aware highlighting and whitespace controls.
Runs locally in your browserFiles are not uploaded or storedNo sign-upPreparing required files for offline use…
How Diff Master compares code
Code Compare applies a line-based diff, then adds language-aware highlighting, optional whitespace normalization and a unified patch-style view.
- Choose TypeScript, JavaScript, Python, JSON or plain text highlighting.
- Paste the original and changed source, then decide whether surrounding whitespace should affect matching.
- Compare locally and switch between side-by-side and Unified Diff results.
Whitespace option
Ignore whitespace normalizes surrounding whitespace for matching while preserving the original source in the result.
Unified Diff
A patch-style view adds familiar plus and minus markers without modifying either input.
Original TypeScript
const retries = 2;
Changed TypeScript
const retries = 3;
Expected result: The changed value is highlighted in both side-by-side and Unified Diff views.
Code comparison FAQs
Practical answers about how this tool compares content, what stays local and where its current limits are.
Which code languages can I select?
The current editor provides TypeScript, JavaScript, Python, JSON and plain-text highlighting. The comparison itself remains line based, so other text-based source can still be reviewed as plain text.
Does Code Compare support syntax highlighting?
Yes. Select a supported language before comparing and Diff Master highlights the code in the side-by-side and unified results without executing it.
Can I ignore whitespace changes?
Yes. Enable Ignore whitespace before comparing. Diff Master then normalizes surrounding whitespace for line matching while keeping the original code visible in the result.
Can I switch result views?
Yes. Side by side is the default and shows the complete aligned file with line numbers. Unified diff is also available for code when you prefer patch-style review.
Is my source code uploaded or executed?
No. Source code is compared locally in your browser and is not executed, uploaded or stored by Diff Master.