Similar line and word comparison, not a git repository tool. There is no commit or branch.

Is Side by side two panes?

No. It is one column of sequential added and removed hunks. Unified is the patch format.

Can I diff binary files?

No. Paste text or UTF-8 files such as .txt, .md, .json, or .csv.

Does Copy match the on-screen view?

Copy is always the unified patch, even if you are looking at Side by side or Word diff.

Should I pretty-print JSON first?

Yes, if you want cleaner diffs. Format each side with JSON Formatter, then paste.

Diff Checker

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About Diff Checker

Paste Left and Right, or upload two text files (one per side). Options: Word diff, Ignore whitespace, Ignore case. Tabs: Side by side (default) and Unified. Side by side is a single column of added and removed lines, not two panes. Unified is a patch with three lines of context. Copy always copies that unified patch, even when Side by side is selected.

This is not a git repo tool. Binary files are not compared. Ignore case lowercases both sides before the diff. Ignore whitespace collapses runs of spaces and tabs. Word diff changes the on-screen list; the copied patch stays line-based.

How to use Diff Checker

1Paste left and right, or upload two files. Left is original. Right is changed. Each side has its own drop zone.
2Pick a view. Side by side lists + and minus lines in one column. Unified is a patch.
3Tune options. Word diff, Ignore whitespace, Ignore case. Ignore options rewrite the inputs before compare.
4Copy the diff. Copy always copies a unified patch, including three lines of context.

Views and copy

The header shows +added and minus removed. Identical inputs show (identical). Upload accepts .txt, .md, .json, and .csv, 15MB per side. Paste is not size-capped. Tens of thousands of lines can be slow; there is no hard line cap.

Drop zones are separate: Upload left file and Upload right file. You cannot drop two files into one control.

Limits and privacy

Both sides stay in your browser. Files are not uploaded. Each upload is 15MB max. No account. Closing the page drops the texts.

FAQs

Is this git diff?: Similar line and word comparison, not a git repository tool. There is no commit or branch.
Is Side by side two panes?: No. It is one column of sequential added and removed hunks. Unified is the patch format.
Can I diff binary files?: No. Paste text or UTF-8 files such as .txt, .md, .json, or .csv.
Does Copy match the on-screen view?: Copy is always the unified patch, even if you are looking at Side by side or Word diff.
Should I pretty-print JSON first?: Yes, if you want cleaner diffs. Format each side with JSON Formatter, then paste.