Paste the original text, then a line containing only =====, then the changed text. Lines starting with + were added, lines starting with - were removed, and unchanged lines are shown with two spaces.
Text diff checker is a free online tool by Hack the Hydra. Compare two texts and see added and removed lines. Optional ignore case and whitespace. Free, private, runs in your browser, no upload.
What it compares
The tool compares line by line using the longest common subsequence, the same idea behind the Unix diff command. A line that changed shows as one removed line followed by one added line. It is meant for text, config files, lists and code snippets, not for binary files.
Ignoring noise
Tick "Ignore extra spaces" to treat tabs and runs of spaces as one space and to ignore leading and trailing spaces, which hides indentation-only edits. Tick "Ignore upper/lower case" when only capitalisation differs. Ticking "Show only changed lines" hides the unchanged context so long files stay readable.
Size limit
The comparison runs in your browser and needs memory proportional to the product of both line counts, so it is limited to roughly 2000 lines per side. For larger files use a command-line diff.
How to use
- Paste the original text in the box.
- On a new line type ===== (five equal signs), then paste the changed text below it.
- Read the result: + marks added lines, - marks removed lines. Copy or download it.
FAQ
Are my texts uploaded?
No. Both texts are compared by JavaScript in your browser and never leave your computer.
Why is the separator needed?
The page has one text box so it stays simple and works on phones. The ===== line tells the tool where the first text ends.
Does it compare word by word?
No, only whole lines. A one-word edit appears as a removed line and an added line.
Can I use it for code?
Yes, for snippets and config files. For whole repositories use git diff.
Hack the Hydra