Mirela
You know how you open an app or visit a website and you expect it to be available your language? It often happens that the app doesn’t have a translation for the language you’ve chosen. That’s where the fallback language comes in.
A fallback language is the language a program falls back on when your preferred option isn’t available. Without it, your users might see broken text, missing labels, even raw code instead of words. With it, they at least get a complete experience, even if it’s not in their preferred language.
How fallback language works
A fallback language is part of your localization logic or system. When content in the user’s preferred language isn’t available, the system automatically tries the fallback language you set. This process continues until it finds a language available with the corresponding text or terminates if none matches.
The logic can sit in your codebase or localization management platform. The ICU Message Format and tools based on it, for example, handle fallbacks by specifying language preferences hierarchically in settings or resource bundles.
How do you choose the appropriate fallbacks?
Picking the fallback language isn’t just a technical decision; it’s a cultural one. It’s important to select fallback languages that users are familiar with or likely to understand. For example, if your main audience is in a multilingual region like Switzerland, your fallback for one of the official languages could be another official language within the country, because many users will know both.
It goes without saying that you should avoid fallbacks to overly distant or unrelated languages, which can confuse users. Always think about the sociolinguistic contexts and user expectations to keep the fallback relevant.
How do you approach fallbacks?
Ok, but how do you implement fallbacks?
Content quality matters in fallbacks too
Your fallback language content represents your brand whenever the primary language version is missing. Naturally, you want to treat this content with the same professionalism as your main language support. So use professional translators or native speakers because that’s the best way to ensure the fallback language text is high quality. Keep your language style consistent to preserve brand voice even in fallbacks.
Establish a clear fallback hierarchy
A fallback hierarchy defines which language appears next when the preferred content is missing. Limit the depth of fallback chains to avoid complexity. Two or three layers work best. Like if the user’s original language is Catalan, the closest regional language would be Spanish, while the global default language is English. Where possible, fallbacks should account for regional or variant language differences.
Provide UI signals about language fallbacks
If you show app or website fallback content, you might want to communicate this to the user. Sometimes, the fallback causes shifts in terminology, tone, or user interface text, so a simple text helps users feel informed. You could add a subtle badge or message and say something like “Content shown in English as fallback,” so users are aware of what’s happening.
Test fallback language scenarios early and often
Testing is one of the most important things you can do. Check whether fallback content displays correctly, how UI adapts to different fallback languages, if messaging about language switching works, and the consistency and branding of fallback text. Automate these tests as part of your continuous integration where possible.
Setting fallbacks with POEditor
If you’re using POEditor for your localization projects, setting fallback languages is simple and flexible. By default, POEditor lets you fill empty translations in any language export with translations from another language in your project, called the fallback language.
You can set a project-level fallback language in the project’s Settings, which applies to all exports unless overridden. For more precise control, you can set an individual fallback language per export under Export > Advanced Options on the language page. This setting only affects your user and overrides the project fallback.
If you use code hosting integrations, you can add export rules with fallback languages linked to those integrations under Settings > Add export rule.
Both project-level and individual fallbacks can also be managed via POEditor’s API using the appropriate methods with the fallback_language argument.