What is a text diff?
A text diff (short for "difference") is a comparison between two versions of text that highlights what has been added, removed, or changed. The term comes from the Unix diff command, which has been used by programmers since the 1970s.
When do you need text diff?
- Comparing two versions of a document before and after editing
- Checking what changed between two versions of a contract or agreement
- Comparing code snippets to find bugs
- Verifying that a translation matches the original
- Checking if two similar texts are identical or have subtle differences
- Reviewing content changes made by a collaborator
How to read a diff
In a typical diff view:
- Green highlighted lines — Added (new content in the modified version)
- Red highlighted lines — Removed (content present in original but not in modified)
- Grey/unchanged lines — Same in both versions
Inline vs side-by-side diff
Inline diff shows everything in one column with additions and deletions marked inline. Good for seeing context around changes.
Side-by-side diff shows original on the left and modified on the right, with matching lines aligned. Good for comparing large blocks of text.
How to compare texts online free
- Go to Text Diff Checker
- Paste your original text in the left panel
- Paste the modified text in the right panel
- View highlighted differences instantly
- Switch between inline and side-by-side view
- Use "Ignore whitespace" option to focus on content changes
Practical uses
Contract review
Paste the original contract on the left and the revised version on the right. Every change is immediately visible — no need to read the entire document.
Content editing
Compare your draft with a colleague's edits to see exactly what they changed.
Code comparison
While dedicated tools like GitHub exist for code, a text diff is useful for quick comparisons without setting up version control.