The Cloud Translation API is priced monthly based on usage. This page states usage fees and notes price differences between v2 and v3. Translation usage is calculated in millions of characters, where 1 million = 106 characters.
Prices per month
|Translation API version||Feature||1–500,000 characters||500,000 –1 billion characters|
|Translation API v2, v3||Language detection||$20 per 1,000,000 characters*||$20 per 1,000,000 characters*|
|Translation API v2||Text translation||$20 per million characters||$20 per million characters|
|Translation API v3||Text translation||Free*||$20 per million characters|
|Translation API v3||Text translation (AutoML Models)||Free*||$80 per million characters|
If you pay in a currency other than USD, the prices listed in your currency on Cloud Platform SKUs apply.
* Price is per character sent to the API for processing, including whitespace characters. Empty queries are charged for one character. Google charges on per character basis, even if the character is multiple bytes, where a character corresponds to a (code-point). For example, translating "こんにちは" to English counts as 5 characters for the purposes of billing. The free tier is only available for Translation API V3.
Prices are 'pro rata' (proportional and incremental). Charges are scaled to the number of characters actually provided to the service. For example, if you send 75,000 characters for processing within a month, you are charged $1.50.
This pricing is for applications on personal systems (for example, phones, tablets, laptops, or desktops). Please contact us for approval and pricing to use the Translation API on embedded devices (for example, cars TVs, appliances, or speakers).
If you are requesting translation or language detection for over a billion characters per month, then contact a sales representative to discuss discount pricing.
Google Cloud Platform costs
If you store documents to be translated in Google Cloud Storage, or use other Google Cloud Platform resources in tandem with the Translation API, such as Google App Engine instances, then you will also be billed for the use of those services. See the Google Cloud Platform Pricing Calculator to determine other costs based on current rates.
To view your current billing status in the Cloud Console, including usage and your current bill, see the Billing page. For more details about managing your account, see the Cloud Billing Documentation or Billing and Payments Support.