Here’s my experience with some premium translation tools, or why gem i18n-tasks is the best.

Weglot #

At 🇦🇹 one previous company we used Weglot to translate the app directly in the browser.

Weglot does not really support Turbo Drive. We had big troubles making it work.

A basic installation looks more-less like this:

# app/views/layouts/application.html.erb
<script type="text/javascript" src="" data-turbo-track="reload"></script>
<%= javascript_tag nonce: true, "data-turbo-track": "reload" do -%>
  Weglot.initialize({api_key: "mySecretKey", wait_transition: true});
<% end -%>

Using Weglot was an expensive mistake.

Phrase #

At 🇫🇷 another company we used Phrase.

To manage translations in our app, we used a Phrase CLI tool.

The phrase config file looked more-less like this:

# /.phrase.yml
  access_token: foo
  project_id: bar
    - file: ./config/locales/<locale_name>.yml
        file_format: yml
    - file: ./public/locales/<locale_name>.json
        file_format: i18next
        fallback_locale_id: bazz
        include_empty_translations: true
        tags: frontend

The workflow looked like this:

  1. Developer adds translation in app like <%= I18n.t('posts.index.title) %>
  2. Developer goes to Phrase Strings app, adds to en locale key=posts.index.title, value All posts
  3. Translate (automatically $) or manually with ChatGPT to other locales inside the Phrase tool.
  4. run phrase pull to replace locales in the app with the updated locales from Phrase.

This process had a lot of friction, but the last drop was when they spiked up the price to EUR 750/month!

Phrase price spike

In complete desparation, I asked on Twitter, and I was recommended the gem i18n-tasks.

Finally, the perfect gem i18n-tasks #

The new workflow looks like this:

  1. Developer adds translation in app like <%= I18n.t('posts.index.title) %>
  2. Developer goes to Phrase Strings app, adds to en.yml locale posts.index.title, value All posts
  3. To translate to all available locales, run i18n-tasks translate-missing --backend=openai.

Here I just added a translation key and run the command. It was auto-translated in all the other YML files:


The task does not override existing translations, so you can override a translation manually if required 🤠.

Generate OpenAI API keys here.

To make the API work, keys should be kept in /.env. To ensure they work in your environment, run:

# .env
export OPENAI_MODEL=gpt-4o

To check translation yml files for errors, run all commands from: /test/i18n_test.rb.

Be sure to have your application i18n defaults set:

# config/application.rb
  config.i18n.default_locale = :en
  config.i18n.available_locales = %i[en fr nl es de it pl pt ro ua]

Gem i18n-tasks is great and I award it my personal gem of the month award! 🥇

P.S. I also tried gem instant18n, but the approach is “Too AI-dependent, too non-canon”. You can learn more about Rails i18n conventions here.