Allow users to improve Firefox Translate results by storing their own translation corrections locally — similar to Microsoft Word’s custom dictionary feature.

[Kurniawan]

Currently, Firefox Translate automatically detects and translates pages using on-device models. However, users have no way to correct translations that feel unnatural or inaccurate for their local language.

I propose adding a “Custom Translation Dictionary” feature that works like the spellcheck dictionary in Microsoft Word:

When users see a translated phrase that feels wrong or awkward, they could right-click it and choose:
→ “Add custom translation…”

Firefox would then store the corrected translation locally in a file (for example, translate_user.json).

During future translations, Firefox checks the user’s local dictionary first.
If a matching phrase exists, it uses the user’s preferred translation instead of the built-in one.

Optionally, users could export or submit their dictionary to Mozilla, helping improve community translations.

Why this matters:

Many expressions, idioms, and slang terms vary by region and culture.
Allowing users to store and refine their own translations makes Firefox Translate more natural and adaptable.

This feature empowers communities to crowdsource better translations without relying on external AI services.

It also aligns with Firefox’s focus on privacy — everything is processed locally unless the user explicitly chooses to share their data.

Example use case:

Default translation: “Reload” → “Muat ulang”
User prefers: “Segarkan”
Firefox remembers this correction for future translations.

Over time, these personalized dictionaries could grow into valuable language resources that Mozilla can integrate into future translation models.

Optional extra:
Add a small “Suggest better translation” button next to translated text.
This could either store the suggestion locally or submit it (with user consent) to Mozilla’s localization platform (Pontoon).

Conclusion:
This feature would make Firefox Translate more flexible, more community-driven, and more aligned with real-world language use.
It also opens the door for users to teach Firefox their language — just like adding words to a spellchecker.

[Jon]

Thanks for submitting an idea to the Mozilla Connect community! Your idea is now open to votes (aka kudos) and comments.

[marco]

Thanks for the idea @Kurniawan, this is along the lines of https://connect.mozilla.org/t5/ideas/have-the-possibility-to-make-a-feedback-about-a-wrong/idi-p/442..., which we have started investigating. You idea would also allow us to crowdsource sample sentences and not just overall feedback.

Correcting translations might actually not be that easy though, because they also depend on the context. A given subset of a sentence might mean completely different things in different contexts.

[ghostbb]

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