Diff Checker & Text Compare

A diff checker (or text compare tool) shows the differences between two pieces of text. It highlights lines or words that have been added, removed, or changed, making it easy to spot what changed between two versions of a file, document, or code snippet.

Yes. All comparison happens locally in your browser. Your text is never sent to a server, logged, or stored. You can safely compare sensitive data such as API responses, configuration files, or personal documents.

The tool supports three diff modes: Lines (best for code and structured text), Words (good for prose and natural language), and Characters (finest granularity for short strings). Choose the mode that best suits the type of text you are comparing.

Split view shows the original text on the left and the modified text on the right, side by side. Unified view stacks additions and deletions into a single column with line numbers, similar to the output of the `git diff` command.

When enabled, the diff algorithm ignores spaces, tabs, and line breaks when matching tokens. This is useful when you want to compare the semantic content without flagging formatting-only changes such as re-indentation or trailing spaces.

When comparing line-by-line, the tool can also show exactly which characters changed within a modified line. Added characters are highlighted in green; removed characters are highlighted in red. This is especially helpful for spotting tiny edits in long lines.

Yes. In line mode, you can copy the unified diff to your clipboard or download it as a plain text file. The output follows a standard unified diff format with +, -, and space prefixes, compatible with tools like Git and patch.

The tool runs entirely in your browser, so the limit depends on your device's memory. It handles thousands of lines comfortably. For multi-megabyte files, a command-line tool such as `diff` or a specialized desktop diff viewer may be more appropriate.

Yes. Click the Swap button to exchange the original and modified texts instantly. This is useful when you pasted them in the wrong order or want to see the inverse perspective of the changes.

Yes. The diff checker treats input as plain text, so it works with any format: source code, JSON, XML, CSV, Markdown, configuration files, prose, and more. For semantic comparison of structured data, use the JSON Diff tool instead.