Translate the entire app to 103 languages: A DIY tutorial

Saltar - a simple web builder, is recently released. We are lucky to be picked up by a local-news, which caused the number of users to shook up.

What interesting was the number of non-English speakers is significance. More than half of the users are Spanish speakers (according to Google Analytics). Also, I recently came across a tutorial on using Google Translate in Spreadsheet. So I decided to add more languages to Saltar using Spreadsheet, some frontend and backend code put together.

To be fair, there were nearly 400 phrases need to translate. Which includes single words like Submit, Cancel, or longer phrase messages like What do you want this page called, when it has 10 million viewers a month?.

This translation method comes with a few issues that I was aware of. For example:

  • Word confusion: when I use “state”, in mouse event (hover state, active state, etc…), it translated “state” as a region
  • Phrase confusion: as we use a shorter form of phrases, the translation result might be different. For example, using “How it works” instead of “How does it works?”. To fix this, use a longer form that has the correct English grammar.

On the other hand, the solution provides a free and quick way to translate the app. Using a spreadsheet also allows you to fix the translation later. It worths a try.

The following content is step by step about how to translate the entire app.

1. Prepare the SpreadSheet

The goal of the spreadsheet is to only fill in the default languages. Then use the formula to translate the rest. I organized the spreadsheet as follows:

  • Each column represents a language. The first column is reserved for the default language, which in my case is English.
  • There are 3 important rows. The first one is the name of the language, which includes its English name and native name. For example, Vietnamese (Tiếng Việt). Then the second row is its ISO 639-1 code, such as “en” for English, or “vi” for Vietnamese. And the last one contains the GOOGLETRANSLATE formula

I have prepared a spreadsheet template, you can find it at the end of this post

2. Translate the SpreadSheet

Once the spreadsheet is ready, all I have to do now is find the phrases, then fill them into the first column.

Note: The client library provides a method, which returns a list of not-translated phrases. You can get the list, then use Paste Special option on Google Sheet.

In the second column, start translating by using the formula:

  • =GOOGLETRANSLATE(sourceValue, sourceLanguageCode, targetLanguageCode)

Repeat to all other languages, for all phrases (see details in the spreadsheet template at the bottom). Then download as .csv (File > Download > Comma-separated…)

3. Setup a server handler

Leaving the language packages on the client-side isn’t a great idea. Since in my case, it added up to 0.5-MB in the total bundle size. While only 2 languages are required at a time (the default and the user-selected ones).

I decided to set up a server, which allows the client to pull only 2 languages it needs. The language database is the CSV file downloaded in step 2. The server APIs include:

  • [GET] /languages/list : listing all the available languages
  • [GET] /languages/:code1,:code2…?version=:version : Request multiple language packages (using version to check for changes)

Every time a request comes in, it reads metadata of the CSV file, gets the date, and match the “version” in the URL query. When the version is either empty or different, it loads the languages and sends back as JSON.

4. Setup client library

The main job of the client library is to get the requested language, then display it. Each time the app started, it makes a request to the server and downloads the new language package if there are any changes.

Here is how the client library looks like (translate English to Vietnamese):

// use either i8.text or i8.t

i8.text("Hello there") 
// => Xin chào
i8.text("Your app __name__ is being created", { data: { name: "Booking" }})
// => Ứng dụng Booking của bạn đang được khởi tạo
i8.text("Update", { case: "upper" }) 
// => CẬP NHẬT

The above example demonstrates 3 common cases for the translation. Which are, (1) a plain text, (2) text with a dynamic variable (using placeholder), (3) and addition options (text case transform).

Note: there are many cases that the library didn’t cover (since the app doesn’t require). For example, currency sign and conversion.


To wrap up, the whole point is to help someone who can’t understand English, have a fair idea about the app and its functionalities.

Translate the app using a spreadsheet isn’t as sophisticated as some of the translate services out there. Though it did an ok job, free and simple

You can download the available resources, follow the instructions to install client and server library. Or making your own translation library as you wanted from the following links

Feel free to give me feedback and share the solution.

The content is originally posted on about saltar com/blog

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