The "Too many translation keys" error in Shopify occurs when you reach the limit of translation keys set by the Shopify team for any secondary language you add to your store.
There is an official number given as a limit by the Shopify team, this occurs after you reach 3400 keys in your theme for locale file.
This can be found in their own documentation here.
What are translation keys?
Every theme comes with its own translatable resources. Some come with the theme by default and are stored in the theme locale files like en.default.json, fr.json, de.json, etc. Others are created when you add content through:
Your theme Customizer
Through a Third-party page builder app (Like "Ecomposer" for example)
Creating a lot of page templates in Shopify (or page builder apps), floods your theme with translation keys and you might get this error when you start translating the given pages.
Why is there such a limit?
The limit comes from Shopify itself and not from the translation app or from the page builder app that you use.
Shopify has stated that this limit is in place for "performance reasons", although they have not placed the same limit for the primary language. (only for the secondary languages)
How to resolve the "Too many translation keys" error?
To solve this error, you’ll need to reduce the number of translation keys in your theme. To do that:
First, you need to identify the source of the excessive amount of translation keys - if you have created a lot of page/product templates in your theme Customizer and try to reduce the amount of resources in them.
In case you have a page builder app that supports the multi-language feature in Shopify, check the page templates.
Whether you have flooded your theme with too many translation keys through the theme Customizer or with a third-party page builder app, the solution is the same:
Remove the unused resources first - instead of hiding an unused resource in the builder, delete it, so it does not count towards the keys limit
Merge duplicated keys - If you have multiple translation keys that serve a similar purpose, consider merging them into a single key
Merge duplicated templates - in most cases, merchants reach the translation keys limit because they create a separate product template for each product in their store, even though the whole product template is exactly the same. This results in duplicated content:
Please consider removing duplicated product templates into a single one, that's used by multiple/all products.
If you are not sure whether all the keys are coming from your theme Customizer or a third-party app, you can either reach the Shopify customer support or ask our support agents to try to identify the source of the excessive amount of resources and translation keys in your store.