Overview

The following is a high-level overview of the technologies associated with Firefox Translations.

Supported Platforms

Desktop
Android
iOS

Note

  • Firefox Translations is available only on devices support SSE4.1 due to required SIMD calculations in WASM.

Language Translation

Firefox Translations utilizes trained machine-learning models that run locally on client architecture to translate web content from one language to another.

Technology

Firefox Translations utilizes a WASM version of the Bergamot library to translate from one language to another. Bergamot is powered by Marian.

Models

Bergamot translation models are single-direction, one-to-one models trained to translate from one language to one other language (e.g. en ⟶ es). When Firefox Translations determines a source language and a target language it utilizes a model specific to this language pair to translate from one to the other.

Pivot Translations

In the event that there is no model to translate directly from a source language and a target language, Firefox Translations will attempt to satisfy a transitive translation path and will perform a multi-step translation from the source language to the target language.

Example

No direct translation model exists
es ⟶ fr

Transitive dependency satisfied
es ⟶ en
en ⟶ fr

Pivot translation
es ⟶ en ⟶ fr

In this example, no direct model exists for es ⟶ fr, but a transitive dependency is satisfied by the two models for es ⟶ en and en ⟶ fr. Firefox Translations will pivot on the en language by first translating from es to en and then from en to fr.

Note

  • Firefox Translations will not pivot more than once.

  • At present, only en is used as a pivot language.

Language Identification

Firefox Translations utilizes trained machine-learning models that run locally on client architecture to identify content as being written in a detected language.

Technology

Firefox Translations utilizes a CLD2 language detector to identify in which language content is written.

Models

No models are currently used for language identification, since CLD2 exists in the Firefox source tree.

Remote Settings

Remote Settings is not currently used for language identification, since CLD2 exists in the Firefox source tree.

Using Firefox Translations

The following documentation describes a high-level overview of using Firefox Translations.

Note

  • Firefox Translations is actively under development and is currently available only in Firefox Nightly.

Enabling Firefox Translations

Firefox Translations functionality can be enabled by modifying the translations preferences in about:config.

These configurations are likely to change as the project develops which is why this documentation links to them in the source code rather than defining them.

At a time when the preferences are more stable, they can be documented here more clearly.

Translating Web Pages

Once Firefox Translations is enabled, Firefox will analyze each web page to determine if it is translatable via the available translations models.

If the web page is translatable, then a translations icon will appear in the URL bar of the browser, allowing the user to initiate the available translation process.

about:translations

When Firefox Translations is enabled, a page called about:translations becomes available in the browser.

This is a test page where there user can select a source language and a target language by typing content into the source-language text box and seeing the translated text in the target-language text box.

Note

about:translations is a developer-focused UI that is useful for testing the state, performance, and quality of the language models in an interactive environment. It is fairly unpolished and not intended to be shipped as a product at this time.

It is, however, useful and fun, so it is documented here.