Compare two files in Notepad++
Notepad++ can compare files, but only after you install a plugin. The steps are below. If you cannot install one — or would rather not — you can do the same comparison here, in your browser, with nothing uploaded.
Text comparison tool
Paste text into both panes, then press Compare.
Does Notepad++ have a built-in compare?
No. This is the first thing most people discover, usually after searching the menus twice. Notepad++ ships without any comparison feature — the functionality comes from the community-maintained Compare plugin, which you install separately. Nothing is wrong with your copy; the feature simply is not there by default.
How to compare two text files in Notepad++
- Open Notepad++ and go to Plugins → Plugin Admin.
- In the Available tab, search for Compare, tick it, and click Install. Notepad++ will close and reopen to finish.
- Open both files, so each sits in its own tab.
-
Choose Plugins → Compare → Compare, or press
Alt + D.
The two files appear side by side with added lines highlighted in green, removed lines
in red, and changed lines marked in both panes. Use Alt + Page Down and
Alt + Page Up to jump between differences, and
Plugins → Compare → Clear Results to exit the comparison view.
On older versions the entry is Plugin Manager rather than Plugin Admin.
If neither appears, your build was compiled without the plugin system — the portable
and 64-bit builds have differed here historically — and you will need to drop the
plugin DLL into the plugins folder manually.
When the plugin route does not work
Plenty of people hit a wall here rather than a minor inconvenience. Corporate machines frequently block plugin installation, or Plugin Admin cannot reach its update server through a proxy. Notepad++ is Windows-only, so it is no help on a Mac or a Chromebook. And if you only need to compare two files once, installing and restarting an editor is a lot of ceremony for a single answer.
The tool above does the same job with nothing to install. Drag both files onto the panes, or paste their contents, and press Compare. It runs in any modern browser, including on machines where you have no administrator rights.
Is it safe to paste file contents into a website?
It is a fair question, and for many online tools the honest answer is "not especially". The reason this one is different is that the comparison never leaves your machine: the algorithm runs as JavaScript in your own browser, there is no API endpoint, and files you drop onto the panes are read locally through the browser's FileReader interface rather than being uploaded.
You can confirm it rather than take it on faith. Open your developer tools, switch to the Network tab, and press Compare — no request carrying your file contents will appear. That is the same property the Notepad++ plugin gives you, without the install.
Which granularity to use
The Compare plugin works line by line, which is the right default for source code and configuration files where a whole line tends to change at once. This tool defaults to the same thing, but also offers word and character granularity. Word granularity is far more readable for prose and for long lines, because it highlights the specific words that changed rather than flagging the entire line as different.
Character granularity is the one to reach for when you are hunting a single typo — a transposed digit in an identifier, or a stray character in a config value that the line-level view marks as changed without telling you where.
Notepad++ comparison questions
Is my text uploaded to a server?
No. The entire comparison runs in your browser using JavaScript. Your text is never transmitted, logged or stored anywhere. You can verify this yourself: open your browser developer tools, switch to the Network tab, and run a comparison — no request carrying your text will appear. The only network activity is the page itself and, if enabled, analytics and advertising scripts, none of which receive what you typed.
How do I compare two text files online?
To compare 2 text files, click the upload button above either pane and choose a file, or drag a file directly onto a pane. Load the original on the left and the changed version on the right, then press Compare. Supported formats include .txt, .md, .csv, .json, .xml, .html, .log and common source code files. The file is read locally by your browser using the FileReader API — it is never sent anywhere, so you can compare two text files without installing software or uploading anything.
How do I compare two text files in Notepad++?
Notepad++ has no built-in compare feature — you need the Compare plugin. Open Plugins, then Plugin Admin, tick "Compare" and click Install; Notepad++ restarts. Then open both files as tabs and choose Plugins, Compare, Compare (or press Alt+D). Differences appear side by side with added and removed lines highlighted. If you would rather not install a plugin, or you are on a machine where you cannot, you can paste or drag the same two files into the panes above and get the same side-by-side result in your browser.
What is the difference between character, word and line comparison?
Line comparison treats each line as a single unit — useful for code and structured data where a whole line changes at once. Word comparison highlights individual words that changed within a line, which suits prose. Character comparison is the most granular and pinpoints single-character edits, useful for spotting typos or subtle changes in identifiers.