How to open a huge HTML file?

On a Mac or Ubuntu box the split command does exactly what you want. The easiest way to use it is with the -l (lines) argument.

1. Open a terminal window.
2. cd to the directory where your giant file lives.

3. Type:

   split -l 5000 filename
   

   where "filename" is the name of your file and 5000 is the number of lines you want in each piece of the file.

4. Your files will be named xaa, xab, etc. by default.

Use Opera. I've successfully opened .html files larger than that using Opera.

  Opera (web browser)
  http://www.opera.com/

There will be an initial delay during loading (because the file is unusually large), but after that all should be well as long as your system isn't low on memory.

If your OS is lousy at dealing with large files, one fix is to install Apache HTTPd to run as a local daemon and then place the 230 MB .html file in the DocumentRoot. From there, you should be able to load it with Opera or Firefox relatively quickly (and probably faster than as a local OS-based file) using something like http://localhost/filename.html as the URI; I use this trick to load large .html files faster under Windows.

The Unix utility less does not need to read the entire file to open it.

less myfile.htm

You can use ↑ and ↓ to scroll, Q to quit.

The split command can also split a many-lined file into separate files:

I'd try to open it in a text-editor like e-texteditor or notepad++ on windows or bbedit or textmate on a mac. These usually will open files that size. From there you can try and split it into smaller pages.