Free Text Diff & Merger

The Text Diff & Merger is a free online tool that compares two texts, highlights differences, and lets you merge them together.

Yes, it is completely free with no registration required. All comparison and merging happens client-side in your browser.

No, the Text Diff & Merger processes everything locally in your browser. No data is sent to any server.

Yes, the Text Diff & Merger is fully responsive and works on smartphones and tablets. You can use it on any device with a modern web browser -- no app download required.

No account or registration is needed. Simply open the Text Diff & Merger in your browser and start using it immediately. There are no sign-up walls or usage restrictions.

Yes, the Text Diff & Merger handles text of any length with fast, real-time processing. Since everything runs in your browser, performance depends on your device but works well for most use cases.

Simply enter your input in the provided field, adjust any settings to your preference, and the tool will process it instantly. You can then copy the result to your clipboard or download it.

The Text Diff & Merger works in all modern browsers including Chrome, Firefox, Safari, Edge, and Opera. For the best experience, use the latest version of your preferred browser.

A two-way merge compares just two versions of your text — an original on the left and a modified version on the right — and shows every line that was added or removed between them. It works well when you only have two copies and want to reconcile them by hand. A three-way merge adds a third input: the common base, meaning the shared ancestor both versions started from. With that base, the tool can tell whether only one side changed a line — which is safe to apply automatically — or whether both sides edited the same line, which is a true conflict that needs your decision. This is the same model version-control systems use, and it produces far cleaner results when two people edited the same paragraph independently. Pick three-way mode in the tool above whenever you have that original base text available.

The tool diffs your text line by line and labels each line as unchanged, added, or removed. When a removed line and an added line sit next to each other, it treats that pair as a potential conflict and runs a word-level diff inside it to show exactly which words moved. In two-way mode you resolve those pairs yourself. In three-way mode, with the common base supplied, it goes further: if only one version changed a given line, that edit is safe to apply automatically; if both versions changed the same line differently, it is flagged as a real conflict that needs a human choice. The auto-merge strategy applies all the non-conflicting changes for you and leaves only the genuine conflicts to settle. Choose your merge strategy in the tool above to control how much it resolves on its own.

The similarity percentage is a quick measure of how alike your two versions are, calculated as the share of lines that match between them. If 90 out of 100 lines are identical, you will see roughly 90 percent similarity, signalling a light edit; a number closer to 40 or 50 percent means the two versions diverged heavily. It sits in the same panel that reports lines added, lines removed, lines unchanged, and the number of conflicts found, so you get an at-a-glance sense of the scope of a change before you start resolving anything. It is a line-level figure, not a character-level score, so reordering words within a line still counts that line as changed. Paste both versions into the tool above to see your similarity score and counts update instantly.

When you finish working through a comparison, the tool offers three download formats. Alongside the finished merged text and a unified-diff patch, you can export a git-style file that wraps any unresolved disagreements in the familiar conflict markers — the rows of less-than signs, equals signs, and greater-than signs that surround the left and right versions. This is handy when you would rather settle certain conflicts in your own editor or commit the file into a repository and resolve it there. The tool also produces a separate conflict report listing each conflict and how it was settled, which is useful for review trails. Resolve what you can in the tool above, then choose the conflict-marker download to take the rest elsewhere.

A line-level diff compares your text one whole line at a time, marking each line as added, removed, or unchanged. It is fast and easy to scan, but when a single word changes inside a long line, the entire line shows as removed-and-added even though most of it is identical. A word-level (or inline) diff drills into that pairing and highlights only the specific words that actually differ. This tool combines both: it diffs by line for the overall structure, then, wherever a removed line and an added line are paired into a conflict, it runs an inline word-level diff so you can see precisely which words moved within that line. You can toggle the inline word highlighting on or off in the tool above depending on how much detail you want while reviewing.