[mattbk1]

Just remember that flags aren't languages.

[lmm]

Flags are the most easily-understood way to communicate languages to users, and I say this as someone who is often obliged to pick the flag of a foreign country (often an empire that wilfully starved millions of my countrymen) to get websites in my native language. "Flags are not languages" is one of those pedantic corrections that ends up doing more harm than good.

[rswail]

The easiest way is to state the language name in that language:

English

עִברִית

العربية

हिंदी

ไทย

etc

[lmm]

How do I find the language selector if the page is in a language I don't know?

[siruva07]

That's a great point.

In that case, I'd suggest the first two letters of the language, an "En" for English, an "Es" for Spanish, a "De" for German, etc.

[ximeng]

https://en.m.wikipedia.org/wiki/List_of_ISO_639-1_codes Not first two letters, two letter ISO codes. There are also complications with dialects, so not quite this simple.