In this article, you'll learn how to get started with translation keys and platforms.

Translation keys are placeholders within the source code of any application—whether it's a website, mobile app, game, or desktop app. When the application is displayed to a user, these keys are substituted with the appropriate translation values based on the user's chosen language setting.

Consider this example from the Ruby on Rails framework:

Here, welcome is the translation key. Translations are typically stored in specialized files. For example, you might have a YAML file containing all the English translations:

And another file for French translations:

When a page is displayed to a user who prefers the English language setting, the key will be replaced with the actual English translation:

If the user switches their language preference to Russian, they will see the message in Russian:

Lokalise provides a streamlined platform for managing translation keys and values, enabling easy upload and download of translation files, among other features.

In the screenshot above, you can see the following:

To add new translation keys to your Lokalise project, you have a few options:

The simplest way to create a translation key is by using our graphical user interface. To get started, open your Lokalise translation project and click Add key:

You'll be presented with the key editor where you can assign the key name, base language value, platforms, and other attributes. Learn more in the Key editor article.

Keys can also be created when uploading translation files, importing content from third-party services by using Lokalise apps, and when using certain API endpoints.

In Lokalise, a key is an identifier for translations in all languages of a project. For example, if you have a key called name and your project supports 3 languages, name will have 3 different translations, one for each language:

You can have as many languages as you need in your project. There are no limits on the length of translations either. In other words, a key can have multiple languages with variable translation lengths.

There is, however, a limit on the number of keys you can have. This quota is set at the team level, meaning it counts all the keys across all projects within your current team. For more details, check out the Team quotas article.

In all cases, Lokalise will still represent your data as translation keys (e.g., DOCX content will be split by paragraphs). These keys will be reassembled into the correct format when exporting.

Due to these specifics, when working with Ad hoc documents and Marketing and support project types, you won't see the Add key button.

One of the unique features of Lokalise is the ability to use similar keys across different platforms, reducing the amount of translation work for translators.

Currently, Lokalise supports four platforms:

When you add a new key, it must be assigned to one or more platforms:

When you upload a translation file, all keys inside will automatically be assigned to the appropriate platform based on the file extension. For example, keys in a JSON file will be assigned to the Web platform.

To link an existing key to a platform, simply find it in the project editor, click on the platform icon, and choose one or more options:

Assigning a key to a platform includes the key in the export routine for file formats compatible with that platform. For example, if a key is assigned to both iOS and Android platforms, it will be exported when Apple .strings and Android .xml formats are chosen. However, it would not be included in a Web .json export (while keys with a Web platform would only go to a .json export).

Here's a partial list of various file formats grouped by platforms that you can find on the Download page:

You can think of platforms as global tags for the keys. If you want all keys to be exported regardless of the platform (for example, if you want to export all data in Excel format), just turn on the Include all platforms option on the Download page:

Developing for different platforms often involves different key naming schemas. For example, iOS developers might prefer LoginButton while Android developers prefer login_button. Lokalise has a solution for this: enable the Per-platform key names option in project settings.

First, click More > Settings in the main menu:

Under the General tab, find the Miscellaneous section and tick the Per-platform key names setting.

Save the changes by clicking the corresponding button at the bottom of the page.

Once this is enabled, when you add a new key (or edit an imported one), you can set a unique key name for each platform.

In the screenshot above, the key is linked to two platforms, and you can switch between these platforms to provide different names.

If you are not done editing your original translation, you can mark the key as Hidden from contributors so that regular (non-admin) contributors can't see it and don't start translating it. Other project admins will still be able to see this key and its translations.

To archive keys so they are not visible in statistics, export, search, and similar areas:

To display all archived keys in the editor: