When I encounter a file of unknown contents, I often open it up in a hex editor or text editor to look inside.
The problem with a hex editor is that I'm usually much more interested in content that I can read than the hexadecimal values. (The exception is the first 256 bytes of the file, in which I may recognize some common file-type signatures.) Hex editors, as their name implies, usually show hex by default or dedicate much of the screen area to hexadecimal.
Text editors also aren't ideal for this task. For example, the popular Notepad++ text editor represents every NUL character with a large 'NUL' indicator. It also doesn't seem to be very good at discerning between ANSI and UTF-8 encodings.
So I'm looking for a gratis file viewer for Windows that allows me to view text and search for strings within the open file. If it has editing capabilities, that's a plus, but not required.
Something that can automatically detect the file's encoding (ANSI, UTF-8, etc.) is a big plus, but not absolutely required.
The ability to show the hexadecimal or decimal value of any character is also a plus, but not a hard requirement.
I prefer to use open-source tools, but I'm okay with closed-source options for this question.
Also, I strongly prefer portable tools, but that's also not a hard requirement for this question.