How it works
The text comparator pits two blocks against each other line by line and marks what stayed the same, what changed, what was added, and what was removed. It uses a longest common subsequence (LCS) algorithm to align the stable lines, so a change in the middle does not throw off the rest of the comparison.
You can choose between a unified view, with + and - prefixes, or a side-by-side view, and enable options to ignore case, spaces, or blank lines when those differences do not interest you. All computation happens in your browser: the texts are not sent to any server.
Use cases
- Detect what changed between two versions of a configuration file, an .env, or a manifest.
- Review the differences between two API responses or two data dumps before investigating an error.
- Compare two lists (dependencies, users, routes) to see which entries were added or removed.
- Contrast two versions of a written or translated text and quickly locate the tweaks.
Frequently asked questions
Does it compare line by line or character by character?
The comparison is line by line: each line is aligned with its equivalent and classified as equal, modified, added, or removed. When a line is modified, the old and new versions are shown together so the change is easy to read.
What do the ignore options do?
"Ignore case" treats uppercase and lowercase the same; "ignore spaces" normalizes tabs and repeated spaces; "ignore blank lines" discards blank lines before comparing. They help you focus on the real changes and not on formatting differences.
What is the difference between the unified and side-by-side views?
The unified view shows a single stream with the added and removed lines interleaved, similar to a git diff. The side-by-side view places the original text on the left and the new one on the right, convenient for reading long blocks in parallel.
Are my texts uploaded to any server?
No. The comparison runs entirely in your browser with JavaScript, so you can compare sensitive content without it leaving your computer.