French to Japanese speech translation API
Stream French (Français) speech and get Japanese (日本語) back in real time. One WebSocket, ISO codes fr to ja, and ultra-low latency for voice agents and live apps.
Trusted by teams building global voice products
Production-ready French to Japanese translation API
Real French speech includes accents, regional dialects, code switching, and domain-specific vocabulary. Soniox recognizes it in a single model and streams Japanese while the speaker is still talking.
French (Indo-European > Romance > Western Romance) and Japanese (Japonic) come from different language families, so word order and morphology differ. Soniox reorders meaning in-stream instead of word by word.
French is written in Latin and Japanese in CJK, so Soniox emits correctly scripted Japanese text.
A breakthrough in real-time French to Japanese translation
Translate before the sentence ends
Japanese meaning lands as French is spoken, not after the caption catches up.
Directional fr to ja streaming
Set the source and target codes once. Both arrive in a single labeled token stream.
High quality Japanese output
Same model across every language, including historically underserved ones.
Native-speaker French STT accuracy
Accurate Japanese translation starts with accurate French recognition across accents and language switching.
Names, numbers, and domain terms
Preserved across the pair, including phone numbers, emails, and IDs.
{
"model": "stt-rt-v5",
"translation": {
"type": "one_way",
"source_language": "fr",
"target_language": "ja"
}
}French and Japanese through a single stream
French to Japanese translation is built on top of Soniox Speech-to-Text API. Every spoken word is transcribed, and Japanese translation streams mid-sentence in the same labeled token stream.
Turn it on by adding a translation block with source_language: "fr" and target_language: "ja". It runs on the same WebSocket and the same model, with no extra round trip.
Live French to Japanese: written and spoken
French to Japanese speech-to-text
Translate live French into written Japanese with the Soniox STT API. Soniox streams the French transcript and the Japanese translation as speech happens.
Use it for Japanese captions, subtitles, meeting translation, agent assist, and multilingual transcription.
French to Japanese speech-to-speech
Build full spoken French to Japanese translation by combining Soniox STT and Soniox TTS. Soniox recognizes French, translates it, and speaks Japanese with low latency.
Use it for live interpreters, bilingual voice agents, travel assistants, and customer support.
Live French to Japanese translation in action
Stream French to Japanese one-way to push all speech into Japanese, or two-way to keep a bilingual conversation flowing between the two languages.
One-way translation
Translate live French into Japanese. Everyone in the conversation sees the same translated stream.
Ideal for live captions, multilingual meetings, broadcasts, lectures, and customer calls.
Two-way translation
Translate between French and Japanese for live bilingual conversation. Each side speaks naturally and hears the other in their own language.
Soniox supports real-time two-way translation between any two of 60+ supported languages.
Accurate on both ends of the pair
Soniox transcribes French at 1.25% word error rate and Japanese at 1.25% word error rate. Accurate recognition on both sides is what makes the translation reliable.
Speech-to-Text
Native-speaker accuracy across 60+ languages, with support for multilingual speech, alphanumerics, speaker diarization, context.
Translation
Real-time streaming translation across 3,600 language pairs, built for high quality and low delay across all supported languages.
Text-to-speech
High-fidelity speech generation in 60+ languages, built for names, alphanumerics, language switching, and ultra-low-latency streaming.
Together, they create a complete real-time low-latency speech AI platform.
About French and Japanese
French has roughly 280,000,000 speakers across France, Democratic Republic of Congo, Canada, and Madagascar. Japanese has roughly 125,000,000 speakers across Japan.
French was the international language of diplomacy and high culture from the 17th to the mid-20th century.
Japanese uses three writing systems simultaneously: kanji (Chinese characters), hiragana, and katakana.
Soniox makes French to Japanese usable in real-time translation across every supported pair.
Translate French to any language
From French to Japanese, or French to any of 60+ supported languages. All real-time.
Frequently asked questions
How do I translate French to Japanese with the API?
Is French to Japanese translation real-time?
What about translating Japanese to French?
Does Soniox handle Latin to CJK output?
Does Soniox handle French dialects and accents?
Which other providers support French to Japanese?
How fast is French to Japanese translation?
Simple, usage-based pricing
Translate live audio from French to Japanese from ~$0.18/hour.
Translation is already built into Soniox Speech-to-Text API. When turned on, it adds about ~$0.06/hour in output token costs.
Ready to get started?
Create an account instantly, or contact us to design a custom package for your business.
Build with APIDocumentation
Get up and running in minutes and spend your time building the product, not wrestling with the API.
Explore docsSee what you’ll pay
Pay only for what you use with our flexible pricing. Built to scale with you.
Pricing details