Text Diff
Two-pane text comparison in line or character mode with green-add / red-remove highlighting — spot every change instantly.
>_ USAGE GUIDE
Paste the old text on the left and the new text on the right; differences highlight in real time — green for additions, red for removals. Two comparison modes cover both scales: line mode shows changed blocks for configs and code versions, while character mode pinpoints exactly which word inside a sentence changed.
- Paste both versions: old text on the left, new text on the right
- Choose a mode: line mode for structure-level comparison, character mode for fine detail
- Read the highlights: green marks what was added, red what was removed; a modification appears as a red/green pair
- Drill down: switch modes to move from changed blocks to the exact characters
Typical uses: comparing two config files, checking contract or copy edits, and answering "which change broke it?". Comparison runs entirely in your browser — nothing is uploaded, so sensitive configurations and private documents are safe to paste.
>_ FAQ
Q1 · Should I use line mode or character mode?
Depends on the goal. For config files, code versions, and multi-paragraph documents, use line mode — changes highlight per line and the structure stays clear. For a single sentence or a paragraph of copy where you need to know which character changed or a space was added, use character mode. A common flow: locate the changed lines in line mode, then switch to character mode for the details.
Q2 · What do the green and red highlights mean?
Red marks removals — present on the left, missing on the right. Green marks additions — present on the right, missing on the left. A modification shows up as a red/green pair at the same position. Some diff tools use yellow for modifications, but underneath it is the same remove-plus-add pairing.
Q3 · Why do two texts that look identical still show differences?
The usual suspects: line-ending differences (Windows CRLF vs Unix LF), invisible characters (full-width spaces, tabs versus spaces, a BOM), or one extra blank line at the end. These hidden differences are the classic reason two files "look the same but behave differently" — and a diff is the most effective way to expose them.
Q4 · Can it compare very large files?
Comparing text at the scale of hundreds of thousands of lines works locally in the browser, but extremely large files consume memory. For hundred-MB logs, preprocess with the command line (diff on Unix, fc on Windows) or extract the relevant sections first. Normal configs, source files, and documents are comfortably within range.
Q5 · How is this different from Git diff?
Same underlying algorithm, different scenario. Git diff tracks changes inside a version-controlled repository; this tool is for any two temporary pieces of text — a colleague sends you a revised config, paste both versions, look, done. No repository setup required, which makes it the faster path for one-off comparisons.