At POEditor, we do not count the words or characters in the software localization projects in your account. What we do count is the number of strings.
What are strings?
As Wikipedia tells us, "[...] a string is traditionally a sequence of characters, either as a literal constant or as some kind of variable." It can be anything from a character to a paragraph. We do not limit the length of the strings you import to your software localization projects in any way.
How do you count the strings?
On an account level (also, the level on which you can make a subscription), the strings are counted as the total amount of terms and translations in every localization project that you own.
For example, say you have one project with 100 terms, translated fully into one language (say, French), and just 50% completed into another language (say, German). This means you have 100 strings (the terms) + 100 strings (French translations) + 50 strings (the German translations). Yup, that's 250 string in your account.
What happens when I reach the strings limit?
You won't be able to add any more strings. That's it.
How can I get more strings?
You can subscribe to a plan with more strings. Please note that the number of strings for each plan represents the maximum number of strings you can store on your account for as long as you have that subscription.
What happens if I downgrade?
You won't be able to add any more strings. Don't worry, none of your data gets erased when you downgrade/go beyond your account's string limit.
Does contributing to another user's project cost me strings?
Nope. All the strings you translate in another user's project are counted against that user's account.
Except for the number of strings in your account, you don't have any other limit on POEditor. You can translate software with the help of as many contributors as you want, create as many localization projects as you like and, also, add an unlimited number of languages to your projects.