GF Offline Translator: text and speech translation for 14 languages with quality control

Speech input: Tap microphone icon and talk while it is red.
Text input: Select "keyboard" from menu, tap keyboard icon.
Correction: Tap input text and edit.
Alternatives: Tap output text.
Grammar info: Tap any of the alternatives.
Confidence: colour of output text

Green: semantic, probably correct (but has alternatives)
Yellow: syntactic, often incorrect (has alternatives)
Light red: chunk-based, probably incorrect (has alternatives)
Dark red: word-based, often very bad

More details

GF Offline Translator is based on grammar and semantics. It is compact in size and gives control on quality. Its technology is inspired by compilers, which are programs that translate computer languages. Most other translators for human language are based on statistics and have less control of quality and are much bigger, so that they require either an internet connection or a huge storage on your phone.

The app indicates translation confidence with colours:

Green: semantic translation, should be correct. But not necessarily the only correct one. You can tap the output to see alternatives.
Yellow: syntactic translation, should be grammatically correct. But can be very strange in its interpretation and choice of words.
Light red: chunk translation, probably incorrect. Builds the translation from small pieces.
Dark red: word-by-word translation, almost certainly incorrect. Builds the translation word by word.

The green translations come from a tourist phrasebook, which allows you to translate things like "hello" and "how far is the airport from the hotel".

You can translate both speech and text, as selected in the menu in the upper right corner. Both kinds of input can be edited with the keyboard by first tapping at the input field. This is often needed because of speech recognition errors. Changing words from upper to lower case may also be needed. At the moment, Japanese and Thai input must be separated to words, whereas Chinese works without spaces.

Translation works between any of the 14 supported languages, which means 182 language pairs in the current version. But different languages are on different levels of development. The following table gives a rough idea of what to expect:

	coverage	quality	speed	speech
Bulgarian				in only
Catalan				in only
Chinese*
Dutch
English
Finnish				in only
French
German
Hindi				in only
Italian
Japanese**
Spanish
Swedish				in only
Thai**

* The speech input for Chinese is Mandarin but the speech output is Cantonese
** For translation from Japanese and Thai you need to separate each word with a space

The speech input and output use Google's voice services. Their status can hence change without notice. You can make it more stable by installing third-party speech tools, such as SVOX, which provides output for most of the listed languages.

When you tap on a translation you get a screen with alternative translations. Tapping on each of the alternatives gives you grammatical information: an inflection table, if it is a single word, and a syntax tree otherwise.

The app also provides an input method which you can use as an alternative keyboard which allows you to do translation from other applications, for instance while you are entering SMS or e-mail. To activate it go to Settings > Language & input.

The translation works completely off-line, without internet connection, when doing text-based translation. Even speech works off-line in some languages, but being on-line may give you better speech input and output and more languages.

You can also install third-party off-line speech engines, such as SVOX. Consult the voice/language settings on your phone to find the optimal speech engines, and restart the app after changing the settings.

The GF Offline Translator is powered by GF, Grammatical Framework. It is open-source software, built by support from the GF community and from Digital Grammars.

Digital Grammars is a company that can tailor this app to you needs and provide good translation for the kind of vocabulary you need. Just tell us what you want to see in the green area!