Diff Checker
Spot the difference between two pieces of text.
About Diff Checker
Side-by-side line-level diff.
How to use
- 1Paste the original text on the left.
- 2Paste the changed text on the right.
- 3Review the highlighted line-by-line diff.
Two pieces of text. What changed? A diff is one of the oldest tools in computing and remains one of the most useful. This checker compares two inputs line by line and shows additions, removals, and unchanged context in a side-by-side view. Useful for diffing config files, prose drafts, JSON payloads, or anything else where "what's different" is the actual question.
Line diff, not character diff
We diff at the line level — like `git diff` and most code review tools. A line is either added, removed, or unchanged. Modified lines show up as a removal of the old line and an addition of the new one. Character-level inline diffing (highlighting which characters within a line changed) is on the roadmap; for now, large structural diffs are far more readable as line-level operations.
Frequently asked questions
Quick answers to the questions people actually ask about Diff Checker.
What kind of diff does this produce?
What kind of diff does this produce?
A line-level diff, like `git diff`. Each line is added (highlighted green), removed (red), or unchanged. Modified lines appear as a paired add + remove. This works well for code, config, prose, and structured data; for line-shaped content it's the right tool.
Is there a character or word-level diff?
Is there a character or word-level diff?
Not yet — character-level inline diffing (showing which substring changed within an otherwise-similar line) is on the roadmap. For now, the line-level view is faster to scan and more reliable on large inputs.
Does it work on JSON?
Does it work on JSON?
On formatted JSON, yes. On minified JSON, badly — everything's on one line. Format both inputs first with our JSON Formatter, then diff them. The same applies to any single-line content.