Text Diff Checker
Paste an original and a modified text to see a line-by-line diff with added/removed lines highlighted. Options to ignore case, whitespace or trailing spaces — all computed locally in your browser.
About this tool
When two versions of a file, a config block, or a query look almost identical, spotting the one changed line by eye is slow and error-prone. This text diff checker compares an original and a modified text line by line and highlights exactly what was added and removed, so the meaningful change jumps out instead of hiding in a wall of matching lines.
It is built for the quick comparisons you do outside of Git — pasting two log snippets, checking a copied API response against an expected one, or reviewing a value someone changed. Options let you ignore case, collapse whitespace, or drop trailing spaces so cosmetic differences do not drown out real ones.
How to use
- Paste the original text into the left (or first) input panel.
- Paste the modified text into the right (or second) input panel.
- Read the highlighted result: added lines and removed lines are marked distinctly.
- Toggle ignore case if capitalization changes are noise for your comparison.
- Enable ignore whitespace or trailing spaces to hide purely cosmetic differences.
- Scroll through to review each change, then fix the source that needs updating.
Features
- Line-by-line comparison with clear add/remove highlighting.
- Ignore-case option so capitalization differences do not clutter the diff.
- Ignore-whitespace and trailing-space options for cleaner, meaningful results.
- Works on anything text-based: code, JSON, logs, config, prose.
- No account, upload, or file size ceremony — just paste and compare.
- Handles large blocks of text without leaving the page.
- Runs entirely in your browser, so private text stays local.
Frequently asked questions
Are the two texts I compare uploaded anywhere?
No. The diff is computed locally in your browser using JavaScript. Neither the original nor the modified text is sent to a server, so you can safely compare logs or config that contain sensitive values.
What does ignoring whitespace actually change?
With whitespace ignored, differences that are only extra spaces or tabs are treated as equal. This is useful when reformatting or indentation changed but the actual content did not.
Does it compare line by line or character by character?
The comparison is line-oriented: each line in the original is matched against the modified version, and whole lines are marked as added or removed. This keeps results readable for code and config.
Can I diff JSON or SQL with it?
Yes. Any text works. For structured formats it helps to format both sides consistently first so that meaningful changes line up rather than shifting due to formatting.
Is there a size limit?
There is no hard limit, but very large inputs take more time and memory since everything runs in the browser. For most real-world snippets and files it is instant.