Offline Translate (CTranslate2)
Translates your subtitles on your own computer, with one small model per language pair. No account, no API key, no rate limits. A pair's model downloads the first time you use it; after that, that pair works offline.
Settings Add-ons Offline Translate (CTranslate2) Install
Subtitld downloads it, checks its SHA-256, and keeps it updated.
- Languages
- 25
- Add-on download
- 23–111 MB
What it does
It runs on your computer with CTranslate2, on the CPU: no account to make, no API key to paste, no cap on how much you translate.
English to Portuguese is one model, Portuguese to English another. Each downloads the first time you translate that way, then works offline.
Subtitld sends one subtitle at a time, as plain text, and keeps each translation beside its original. Formatting such as italics isn't carried over.
Language tags are cut to their main language, so pt-br and pt-pt are both pt. Between two variants of one language, the text comes back unchanged.
Used Google translation before 26.10? The built-in Google engine is gone, and this add-on replaces it, with no API key. Install it from Settings › Add-ons, then pick translate-offline as the Translation engine in the translation panel.
Models
There is no model to pick. Subtitld tells the add-on two languages: the one your subtitles are marked with (Subtitle Language in the transcription panel) and the Target language. The add-on looks up a model made for exactly that pair in Argos Translate's package list. It doesn't translate through a third language: with no model for the pair, you get unsupported_language.
A pair's model is about 60–80 MB. The first subtitle of a new pair waits while it downloads, and the progress bar moves once it is in. After that, translating that pair needs no network.
Where models are kept
Each pair has its own folder, named after it: en_pt, pt_en and so on. They live outside the add-on, so updating or uninstalling it keeps them; delete a folder to free its space.
| System | Folder |
|---|---|
| Linux | ~/.cache/subtitld/translate-offline |
| macOS | ~/.cache/subtitld/translate-offline |
| Windows | %USERPROFILE%\.cache\subtitld\translate-offline |
Options
In Settings › Add-ons › Offline Translate (CTranslate2) › Configure.
2How many candidate translations it weighs for each subtitle. Higher is slightly better and slower; 1 is the fastest.
Languages
The add-on lists these languages. A pair works when Argos Translate has a model for it; regional tags such as pt-br use their main language.
enptesfrdeitnlruukpltrarzhjakohicssvdafielhuroidca
Platforms
| System | Download |
|---|---|
| Linux x86-64 | 110.8 MB |
| macOS (Apple silicon) | 22.8 MB |
| Windows x86-64 | 41.0 MB |
The builds are made in CI, without running a translation.
Troubleshooting
Subtitld stops at the first error and shows it in a Translation error box, code first. Subtitles translated before it keep their translation.
unsupported_languageThere's no model for this pair; the message names it, as inpt->de. The add-on doesn't go through a third language, so choose another pair. If the message says the model files are missing, delete that pair's folder and run again to download it fresh.network_unavailableThe model, or Argos Translate's list of models, couldn't download. Check your connection and try again. Only a pair's first use needs the network.internalSomething else failed, such as a full disk while unpacking a model. A pair counts as ready only once it is fully unpacked, so running again starts its download over.
License
The add-on and CTranslate2 are fine for commercial work. Each model keeps its own license, typically MIT or Creative Commons, so check the one for your pair before you rely on it commercially.
Versions
- 0.1.0