Diff Checker
Diff Checker
Compare two text blocks side-by-side with color-coded line-by-line differences; apply or generate unified diff patches; load files via drag-and-drop; word-level and JSON-aware modes.
Enter or load text in both panels to compare.
Diff Checker
Compare two text blocks side-by-side with color-coded line-by-line differences; apply or generate unified diff patches; load files via drag-and-drop; word-level and JSON-aware modes.
Common uses
- Compare two versions of a config file
- Apply a unified diff patch to text
- Find word-level changes between two paragraphs
Also searched as
- compare two text files online
- side by side text diff online
- highlight differences between two texts
- apply a unified diff patch online
- create a patch file from two texts
- three way merge online
- compare two json files for differences
- word level diff between two paragraphs
- diff ignoring whitespace online
- find what changed between two config files
- winmerge alternative online
Frequently asked questions
How do I compare two texts?
Paste the original on the left and the changed version on the right; differences are highlighted line by line. You can optionally ignore whitespace.
How do I compare two text files online?
Paste or drag-and-drop both texts into the Diff tab of the Diff Checker and it shows a side-by-side, color-coded line-by-line comparison. It runs in your browser.
Can I apply a unified diff patch to text without git?
Yes. The Apply Patch tab applies a unified diff to your original text. On the Diff tab, a Generated Patch section produces a unified diff from your two texts that you can copy or download as a .patch file.
How do I do a three-way merge online?
Use the Three-way Merge tab: provide the common base text and the two changed branches. The tool merges them and counts and marks any conflicts in the result.
Can I ignore whitespace or compare by word instead of by line?
Yes. The Diff tab has toggles to ignore whitespace, case and blank lines, a Words button for word-level highlighting, and a JSON mode that sorts keys so key order is ignored.
Is my data uploaded to a server?
No. This tool runs entirely in your browser — your input is processed locally on your device and is never uploaded or stored on a server.