Langzy’s price structure has two components: a monthly subscription fee, plus a usage-based fee for actual translations.
You can think of this as a cell phone plan. There is a monthly fee which enables access to the service, plus a usage-based fee, which only applies to what you actually consume.
The monthly fee allows us to keep Langzy up and running, and to provide services like translating various file formats, retaining past translations, or enabling automated workflows through Zapier. Exactly how much of these services is available depends on the plan you choose. A short summary is at the bottom of the Langzy homepage, under Subscription plans.
The usage-based fee is there to keep Langzy’s pricing fair. Langzy gives you easy access to many of the best machine translation services, but it doesn’t provide the actual translations. These services all charge based on the amount of text translated, and they each charge a different amount. This is reflected in Langzy’s own volume-based pricing, which you can see on the Balance page in your account, under Prices by MT service provider.