So I wanted to get identicons of Stack Overflow users and decided to try and get the Users.xml file, and opened it in the following:

  • MS Word 2010 - I currently own this version, and the XML file doesn't want to load, and led to an error.
  • Notepad - I tried to open it, but it doesn't support very big files (the one I got was 645 MB).
  • MS XML Editor (not sure which version) - Just like Word, it lead to an error.
  • Code Writer - This one actually scared me. I decided to open it and decided to wait for a long time, until my computer started having issues, like low FPS, and I decided to turn off and on my laptop (Win10), and uninstall the app. I brought it back and there were no more issues.

So none of these work, and now I'm hoping to get an app or a text editor that can handle huge files without crashing the OS.

So is there some app I can use to open big XML files?

  • 1
    Does it have to be an editor, specifically? If the file is that large, it sounds like you'd want to process it with specialized tools (streaming XML parsers), instead of copy-pasting things by hand. (Similar to the answers about huge CSVs.)
    – user1686
    Commented Dec 30, 2020 at 15:25
  • Now that I answered your question, I wanted to suggest another approach to your problem. Once I had trouble working with such a large XML, even though it opened, it was slow for doing regexp searches. So, instead, I wrote an XSL to extract only the elements I was interested into a new file which was much easier to work with.
    – Itai
    Commented Dec 30, 2020 at 15:39

4 Answers 4


There are quite a few. The universal editors that can handle huge files are Emacs and XEmacs. They are both available for most platforms and I have been using those on Linux and Windows 10 where I am frequently work with files in the 100s of MBs. The main thing to know is that these editors load the entire file at once, so if you have enough RAM, it will be fast, otherwise the system will fallback to swap space.

For a Window specific solution, there is a program unsurprisingly called Large Text File Viewer which handles files in the gigabytes. This is good is you want to view files but do not need to modify them. It is a simple binary that can be executed directly without installation.


CudaText editor (it's FOSS) supports big files rather good. Only before the opening, allow big sizes via the option in "user.json":

"ui_max_size_open": 1000,

Then it can load files up to 1000Mb. "Lite lexer" XML^ must support your huge file, https://wiki.freepascal.org/CudaText#Lite_lexers .

Currently few lite lexers are made: XML ^, JSON ^, Log files ^, SQL ^. You can also choose them, from the usual lexers menu (they are visible by suffix).


I have had luck opening 10GB files with Notepad++, in place of my usual Sublime text, which fails at the task.

I think this is because Notepad++ stores the data in RAM (I have 16GB), whereas sublime text opens the file using disk space, of which I have a HDD.

  • 1
    Be aware that if you have a Notepad++ plugin that formats the XML file, there is a good chance Notepad++ will lag tremendously for large XML files. Personally, because I use such an plugin, I have to avoid opening any XML files over 500KB in Notepad++. Commented Dec 31, 2020 at 18:30

For really large files up to 16TB (yes, terrabytes) and beyond I would recommend Em Editor.

Basic functionality is Free and if you want some nice CSV tools and more included it is decently priced.

Some claimed number from their page:

  • Open a 10 GB file: 1.900 seconds
  • Replace string in 1.3 GB file: 0.060 seconds
  • Sort A to Z for 800 MB file: 0.647s seconds
  • Delete Duplicate Lines in 800 MB file: 0.216s seconds

System: EmEditor Professional v22.1.0 64-bit, Windows 11, Ryzen 9 7900X, 64 GB RAM, SSD

Personally I have tested with xml files up to around 11Gb in size and they open in less than a second and search and replace operations are insanely fast.

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