Compare two texts and see every change
Paste two versions of a text, a code file or a JSON document. Every added, removed and changed line is highlighted as you type, down to the changed words.
Diff Checker shows exactly what changed between two versions of anything written: contracts and articles, source code, configuration files and API responses. Lines that only exist on one side are marked as added or removed, and lines that changed are paired up with the changed words highlighted.
Long stretches of unchanged text are folded away so the changes stand out, and Previous and Next take you from one change to the next. Side by side suits wide screens; Inline reads like a git diff and suits phones.
Ignore whitespace and Ignore case hide differences you don't care about. Compare as JSON formats both sides and sorts their keys first, so two JSON documents are compared by their data rather than their layout.
The comparison runs in your browser and nothing is uploaded, so it is safe for private documents and code. When you're done, copy or download the differences as a unified patch file.
What do you want to compare?
- Compare Text - Paste two versions of a document, an email or an article and see what changed. Added and removed lines are marked, and changed words are highlighted inside each line.
- Compare JSON - Paste two JSON documents, such as API responses, package.json files or configs, and see which values changed. Key order and formatting are ignored, so only real data changes show.
- Compare Code - Paste two versions of a function, a file or a config and review the changes like a pull request: side by side or inline, with changed tokens highlighted and a patch to download.
Coming soon
- Compare folders - Drop two folders and see which files changed.
- Merge changes - Pick changes from either side to build a merged version.
- Compare spreadsheets - Cell-by-cell differences between two CSV files.
Frequently asked questions
- Is my text uploaded?
- No. Diff Checker runs entirely in your browser. Neither text is sent to our servers, logged or stored.
- How do I compare two files?
- Press Open file above each side, or drag a file onto each editor. Any text file works: code, Markdown, CSV, JSON, YAML, logs and more.
- What does Ignore whitespace do?
- It treats several spaces or tabs as one and ignores spaces at the start and end of lines, so re-indented code or re-spaced text does not show as changed.
- Can I compare JSON with keys in a different order?
- Yes. Turn on Compare as JSON: both sides are formatted the same way with sorted keys before comparing, so only real data changes are shown.
- What is a patch file?
- A unified diff, the format used by git and the patch command. It lists the changed lines with a few lines of context and can be applied to the original to produce the changed version.
- How large can the texts be?
- Files of several megabytes work. Very large texts with many differences may take a moment, and the comparison stops with a message if it would take too long.