Azure Translator Text API: What is the definition of a character?

The pricing of the Translator Text API belonging to the Azure Cognitive Services family is based on characters.

But what is the definition of a character?

Some examples:

• Do spaces, punctuation and line breaks count as a character?

This is   ,   a     


test.

• When translating HTML does every character count here including angle brackets, tags, slashes etc.?

<p>This is<br>
&nbsp;&nbsp;&nbsp;a
test.</p>

For the sake of completeness: I suppose only the text that is being sent to the API for translation counts (request characters) and not what comes back (response), right?

This is answered here character counts. All of the above examples count as text. Responses do not count. Copying from there:

What counts is:

• Text passed to the Translator Text API in the body of the request

• Text when using the Translate, Transliterate, and Dictionary Lookup methods

• Text and Translation when using the Dictionary Examples method

• All markup: HTML, XML tags, etc. within the text field of the request body. JSON notation used to build the request (for instance "Text:") is not counted.

• An individual letter

• Punctuation

• A space, tab, markup, and any kind of white space character

• Every code point defined in Unicode

• A repeated translation, even if you have translated the same text previously