Diff Checker
Compare two texts side by side with line and character level highlights.
Text Diff Checker
The Diff Checker places two texts side by side and shows visually what was added, removed, or changed. It's built on CodeMirror's merge view, which highlights not only line-level differences but also the specific characters that changed within a line, so you can see exactly what's different.
Paste the original into the left pane and the comparison into the right, and change markers appear between the two panes. Each pane shows line numbers and wraps long lines automatically, so you can comfortably compare code, config files, JSON, logs, or any other text. A single button loads a sample to see it in action, or clears everything to start fresh.
All comparison runs in your browser, and the text you paste is never sent to a server. That means you can compare sensitive config files or internal code without any data leaving your machine.
How to use
- Paste the original text into the left pane and the text you want to compare into the right pane.
- Read the highlights between the two panes to see what was added, removed, or changed — including the exact characters that changed within a line.
- To see how it works, click 'Load sample'; to start over, click 'Clear'.
Frequently asked questions
- Does it show line-level or character-level differences?
- Both. It indicates which lines changed and also highlights the specific characters that differ within a given line.
- What kinds of text can I compare?
- Anything textual — code, JSON, config files, logs, or plain prose. It isn't tied to any particular language syntax.
- How are long lines displayed?
- Line wrapping is on, so long lines fold within the pane without horizontal scrolling. Line numbers are shown as well.
- Is the pasted content sent to a server?
- No. All comparison runs in your browser, and the text is never sent to a server.