📄 Diff Checker & Text Diff
Compare two texts side by side. Additions, deletions, and modifications are highlighted line by line with word-level granularity.
📌 Original Text
✏️ Modified Text
Paste text in both panels and click Compare
How to Use This Diff Checker
- Paste the baseline into the left panel — the version you want to treat as "before".
- Paste the changed text into the right panel. Both panels stay in your browser; nothing is uploaded.
- Click Compare. The tool runs a longest-common-subsequence diff over the two inputs.
- Read the result side by side. Content only on the left is a deletion, only on the right is an addition, and lines that changed on both sides are shown as modified with the changed words highlighted.
- Swap or Clear to flip the comparison direction or start a fresh one. The counter next to the buttons reports how many lines were added, removed and changed.
What Gets Highlighted
| Marker | Meaning | Typical cause |
|---|---|---|
| Removed line | Present on the left only | Deleted config key, dropped log line, removed paragraph |
| Added line | Present on the right only | New environment variable, extra import, appended row |
| Modified line | Both sides, different content | Changed value, reworded sentence, bumped version string |
| Unchanged | Identical on both sides | Context — kept visible so you can read the diff in place |
Because the comparison is word-granular inside changed lines, a single edited number or variable name is obvious instead of being buried in a redrawn line.
What Developers Actually Use It For
- Config drift — compare a working
.env, nginx block ordocker-compose.ymlagainst the version on another machine. - Log comparison — diff two runs to spot the one line where behaviour diverges.
- Reviewing pasted code — a colleague drops a snippet in chat; compare it against your local copy before committing.
- API response diffing — paste the pretty-printed JSON from two responses and see exactly which field changed.
- Prose and documentation — track edits between two drafts without a word processor's revision marks.
Diff Checker vs. Git Diff
git diff is the right tool inside a repository: it knows about revisions, staged changes and rename detection, and it emits a unified patch you can pipe into git apply. This page solves the other half of the problem — two blocks of text that were never in version control, or that live on two different machines. Paste both sides, get a side-by-side visual diff, and nothing leaves your machine.
Related Free Tools
- JSON Formatter & Validator — format, validate and tree-view JSON before comparing it.
- Regex Tester — test a pattern against the lines you just diffed.
- Base64 Encoder and Base64 Decoder — decode an opaque blob so the diff is readable.
- Hash Generator — check two files are byte-identical before you spend time diffing them.