First of all, the new Google Place Autocomplete API is not free (after exceeding the US$200 monthly credit equivalent free usage).
Now coming to the pricing, Google has introduced three possible pricing criteria:
- Autocomplete without Places Details – Per Session
- Autocomplete (included with Places Details) – Per Session
- Autocomplete - Per Request
You might be wondering: What's the difference between session and request?
Session
The session begins when the user starts typing a query, and concludes
when they select a place and a call to Place Details is made. If the
user does not make a selection, the session will end after a short
time out period.
Request
If you don't go with a session-based approach, you'll get billed per search query.
For example, if you type "S", it will increase your request count, now you write one more character "Sa", and it will again increase your request count.
So, if you type the whole word "San Francisco", you'll get billed for 13 requests.
Benefits of using session
As mentioned in the above example, if you don't want to get charged per character that you write, you have an option to combine your search queries into a single session. That way you'll save some bucks to spend somewhere else.
So, the "San Francisco" whole string will be billed as one session request instead of multiple.
Please note that session price is always higher than per request price but it is decided in such a way that if you are heavily using the auto-complete in your project with lots of user-base, then ultimately, session-based pricing becomes cheaper than request-based pricing.
Usually, in my opinion, a session-based approach can be helpful only to those who are having heavy usage of autocomplete, otherwise, the request-based approach is fine.
To do the math, go to Google Pricing Table and scroll to Places.
