The ChrysoKit Text Diff Checker compares two pieces of text and highlights every difference, line by line, word by word, or character by character. View them unified or side-by-side.
Why use it
Reading two versions and spotting the change by eye is unreliable. A diff makes additions, deletions and changes obvious in colour. Everything runs locally, so private docs stay private.
How to use the Text Diff Checker
- Paste the original text on the left.
- Paste the modified text on the right.
- Pick the granularity: Line, Word or Char.
- Switch between Unified and Split view depending on which is easier to read.
Features worth knowing
Three diff modes
Line for code and config files. Word for prose. Char for catching tiny edits inside a single word.
Unified or split view
Unified inlines the changes for compact reading. Split shows old and new side by side, easier for long edits.
Copy as unified diff
One click copies the diff in unified-format text so you can paste it into a PR comment or a chat.
Pro tips
- Word-level diff is better for prose; line-level diff is better for code and configs; char-level for catching typo-grade edits.
- Strip trailing whitespace before diffing if the result is full of meaningless changes.
- For very large files, line-level diff is faster than word-level.
Privacy first. The Text Diff Checker runs entirely in your browser. Nothing you paste is uploaded.
Bookmark the Text Diff Checker next to the JSON Formatter; the two together cover most "what changed?" debugging.
Open the tool: Text Diff Checker →
Three diffs that saved real money
The first was a contract. A supplier sent "the same agreement with the dates updated" for renewal. Pasting both versions into a diff showed the dates were indeed updated... along with a liability cap quietly reduced from 12 months of fees to 3. One highlighted line, caught in thirty seconds, would otherwise have surfaced during a dispute years later.
The second was a broken deployment. A service worked on the staging server and failed in production with identical code. Diffing the two environment config files character by character exposed a trailing space after a hostname... invisible in every editor, fatal to the connection string, and undetectable by eyeball comparison precisely because the two files "looked identical".
The third was an academic submission. A co-author returned a manuscript saying they had "only fixed typos". The word-level diff showed a methodological claim softened from "demonstrates" to "suggests"... a fair edit, but one that needed discussion before the journal saw it, not after.
The pattern across all three: humans are excellent at reading text and terrible at comparing it. Any time someone hands you version B with a verbal summary of how it differs from version A, the summary is a hypothesis. The diff is the evidence.