Utilities
Diff Checker
Ignore whitespace
Ignore case
Original
empty
Changed
empty
Compared entirely in your browser — nothing is uploaded
Tool features
4 features
Side-by-side & unified
Read changes in aligned columns, or copy a Git-style unified diff.
Word-level highlights
Changed lines highlight the exact words that differ, not just the whole line.
Ignore noise
Optionally ignore whitespace and case so reformatting does not show as a change.
Runs in your browser
Text is compared locally with JavaScript and never sent to a server.
What is a diff & how it works
A diff shows the smallest set of line insertions and deletions that turns one text into another. It is how version control, code review and patch files describe changes, and the quickest way to spot what really differs between two configs, API responses or document drafts.
This checker lines up both texts, marks added lines in green and removed lines in red, and for lines that changed runs a second word-level comparison so small edits stand out. The unified view uses the same -/+ format as git diff.
Added / removed
Lines only in the new text (+) or only in the original (−).
Unified diff
One column with -/+ prefixes, the format used by Git and patch files.
Word diff
A second pass inside a changed line that highlights the exact words that moved.
How to use this tool
1
Paste both versions
Drop your original text on the left and the changed text on the right — code, config, JSON, prose, anything.
2
Tune the comparison
Toggle “Ignore whitespace” or “Ignore case” if you only care about meaningful changes.
3
Read the differences
Added lines are green, removed lines are red, and changed lines highlight the exact words that moved.
4
Copy or share
Switch to the unified view and copy a standard +/- diff to paste into a PR, ticket, or email.
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Frequently asked questions
5 Q&A
Side-by-side shows the original and changed text in two aligned columns, which is easiest for reading. Unified view shows a single column with -/+ prefixes (the format Git and code reviews use), which is best for copying into a pull request or ticket.
It treats runs of spaces and tabs as equal and ignores leading/trailing whitespace when comparing lines, so reindentation or trailing spaces won't show up as changes. The original spacing is still displayed.
Yes. When a line is changed rather than fully added or removed, the tool runs a second word-level diff and highlights only the words that actually differ, so small edits are easy to spot.
Yes — it's line-based, so it works for any plain text including source code, JSON, YAML, CSV and logs. Very large inputs (tens of thousands of lines) compare more slowly because matching is done in the browser.