Anyone Here Use Notepad++ for Large Files?

[steeve wick]

I’ve always liked how quickly Notepad++ opens compared to heavier code editors. It’s simple and does the job without using too many system resources.

I was wondering how it handles really large files, though. Things like log files, CSVs, or text files with thousands of lines. Does it still run smoothly, or does it start slowing down once the file gets big?

I’m also curious whether the computer makes much difference. Would a 16GB RAM laptop be perfectly fine for this kind of work, or does performance depend more on the file size and format?

What about you guys?

• Do you regularly work with large files in Notepad++?
• Have you ever had it freeze or become noticeably slow?
• Are there any settings or plugins you use to make it handle large files better?

Would be interested to hear what works for others.

[Mark Olson]

@steeve-wick

The most important things IMHO are:

1. not to open huge single-line files with Notepad++ (henceforth NPP). NPP has several routines that reread the entirety of every line currently visible whenever the user does basically anything, so for example a file with a single 30MB line might be slower to navigate and edit than a 100MB file where every line is less than 1KB.
   • as a corollary, if you have a large single-line file in a storage format like JSON or XML that can be pretty-printed, you may want to pretty-print it and re-save it (JsonTools is good for JSON, and IIRC XML Tools is good for XML, but I assume the command line is faster than either). This will make the document easier to read while also improving NPP’s performance, at the cost of taking up more space on your hard drive.
2. Make sure that Settings > Preferences... > Performance > Large File Restriction is set to some reasonably low number (I prefer 64), since syntax highlighting can really slow down processing of files.
   • In my experience, it doesn’t help performance much to turn off word wrap for huge files, so I would leave Deactivate Word Wrap globally unchecked
3. Try using the HugeFiles plugin for really enormous files if you tried opening them in NPP and the editor was super unresponsive. At the time of writing, HugeFiles can only open UTF8-encoded files, but it allows very fast navigation of any file. It even allows chunking of JSON arrays, although that is currently pretty slow.
4. For global find/replace actions in any large file, I strongly advocate for using the command line or your favorite scripting language rather than opening them in any text editor (including Notepad++) and using the text editor’s find/replace functionality. The point of a text editor is that you can easily scroll through a file and do a sanity check to make sure that for example a find/replace action made appropriate changes. But those advantages don’t really apply when you have a 400MB file and the find/replace action is going to make 30,000 replacements. At that point you are much better opening a Python session and taking advantage of its full Turing-complete power to test the waters before committing to a change.
5. If you suspect that a plugin is causing performance issues, try disabling that plugin.
   • Be careful about plugins that automatically do costly actions like parsing the entire file when you open a file. If the plugin has a setting to disable automatically doing things like that, turn that setting off. Alternatively, switch to a similar plugin that doesn’t automatically freeze Notepad++ when you open a ginormous file.

[steeve wick]

@Mark-Olson That’s really helpful, especially the point about a huge single-line file being slower than a much larger file with shorter lines. I hadn’t considered that line length could make such a big difference to Notepad++ performance. I’ll definitely take a look at the Large File Restriction setting and the HugeFiles plugin as well. Thanks for sharing all these details!