yukiko
NaturalHD Japanese female, yukiko. Bright and real-time optimized.
Language: Japanese
Country: Japan
Gender: Female
Accent: Japan Kansai
Japanese TTS API Voices
Generate lifelike Japanese speech across a wide range of voices and every major accent, over carrier-grade infrastructure built for voice agents and IVR.
Pay as you go from ~$3 per 1M characters, no commitment
Built on the same infrastructure thousands of teams ship voice on
14,000+
companies build on Telnyx
100+
languages & dialects
1,300+
voices, one API
<500ms
end-to-end latency
Japanese voices & accents
Japanese voices across every major regional accent. Hear them below, or browse the full catalog by country.
Call the Japanese TTS API
Generate Japanese audio in one request. OpenAI-SDK compatible, with streaming for real-time apps.
cURL
curl -X POST https://api.telnyx.com/v2/text-to-speech/speech \
-H "Authorization: Bearer $TELNYX_API_KEY" \
-H "Content-Type: application/json" \
-d '{
"voice": "Telnyx.NaturalHD.ja-JP-1",
"text": "処方箋の準備ができましたので、薬局でお受け取りください。"
}' --output sample.mp3Node
import OpenAI from "openai";
const client = new OpenAI({
apiKey: process.env.TELNYX_API_KEY,
baseURL: "https://api.telnyx.com/v2",
});
const audio = await client.audio.speech.create({
model: "Telnyx.NaturalHD",
voice: "ja-JP-1",
input: "処方箋の準備ができましたので、薬局でお受け取りください。",
});Python
from openai import OpenAI
client = OpenAI(
api_key=os.environ["TELNYX_API_KEY"],
base_url="https://api.telnyx.com/v2",
)
audio = client.audio.speech.create(
model="Telnyx.NaturalHD",
voice="ja-JP-1",
input="処方箋の準備ができましたので、薬局でお受け取りください。",
)Voice IDs follow the Telnyx.<Tier>.<Voice> convention, so you can swap the voice without touching the rest of your code.
Read the TTS docsWhat teams build with Japanese TTS
Voice agents & IVR
Natural Japanese phone agents that handle calls end-to-end, carrier-grade.
Customer support automation
Bilingual support flows that resolve common requests without a queue.
E-learning
Narrate Japanese courses and lessons in any regional accent.
Audiobooks
Long-form Japanese narration with consistent, lifelike delivery.
Video voiceover & dubbing
Localize content into Japanese at scale with named native voices.
Accessibility
Japanese screen-reading and read-aloud for inclusive products.
Browse all Japanese voices by country
Infrastructure for TTS Library, courtesy of Telnyx
The delivery path, model breadth, low-latency pipeline, and economics behind every voice above.
The stack quality Japanese TTS needs
01
Delivery path
24 kHz audio has to survive the phone network. Without a carrier-grade delivery path it gets crushed to 8 kHz, throwing away the quality the model produced. Own the delivery, or the voice degrades before anyone hears it.
02
Model layer
No single engine wins every language, accent, and budget. Front many models (Telnyx, AWS Polly, Rime, Inworld, ElevenLabs, and more) behind one API so you can swap by config instead of re-integrating each time.
03
Real-time pipeline
For voice agents and IVR, TTS alone isn't enough: TTS, STT, LLM, SIP and numbers belong in one path under ~500ms end-to-end, or the back-and-forth feels laggy and robotic.
04
Economics
Predictable per-character, pay-as-you-go pricing, no seats, minimums, or surprise overage tiers, is what keeps quality voice affordable once you scale past a demo.
Enterprise-grade trust
SOC 2 Type IIHIPAAPCI DSSGDPRISO 27001 / 27701STIR/SHAKEN A-level
Owned infrastructure in 20+ countries, PSTN reach in 100+ countries, used by 14,000+ companies.
Japanese TTS pricing
From ~$3 per 1M charactersPay as you go. No commitment, no seats.
| Model | Per character | Per 1M characters |
|---|---|---|
| Telnyx (standard) | $0.000003 / char | ~$3 / 1M chars |
| Telnyx HD | $0.000048 / char | ~$48 / 1M chars |
| Bring-your-own (ElevenLabs, Azure) | Your provider's rate | Billed through Telnyx |
Qualifying startups can apply to the Telnyx startups program for up to $20K in credits. Volume discounts available on the Growth Plan.
Start buildingStart building with Japanese TTS
Japanese voices, carrier-grade delivery, from ~$3 per 1M characters.
Pay as you go. No commitment. Business email required.
Japanese text to speech FAQ
Japanese text to speech (TTS) converts written Japanese into natural-sounding spoken audio using AI voices. Telnyx exposes Japanese voices through one API for apps, IVR, and voice agents.
Japanese phonology and prosody
Every mora gets its time
English is stress-timed[1]: stressed syllables recur at roughly even intervals while unstressed syllables collapse toward schwa. Japanese runs on a different clock: it is mora-timed[2], where each mora receives roughly equal duration. "Interesting" in casual English compresses to something like in-trst-ing[3]; a comparable Japanese word keeps every mora evenly spaced. A TTS system trained on English stress-timing imposes the wrong rhythmic skeleton on Japanese output. Producing natural mora-timed speech requires models that control sub-syllabic duration at inference, co-located with the audio pipeline so timing information survives intact.
Pitch accent carries meaning
English marks word identity through lexical stress[1]: louder, longer, higher-pitched syllables: as in REcord (noun) vs. reCORD (verb). Japanese replaces that mechanism with pitch accent[2]: meaning depends on where pitch falls across morae, not on loudness or duration. The triplet 箸 / 橋 / 端 (chopsticks / bridge / edge) differs primarily in pitch contour[3], not stress. An engine that maps English stress cues onto Japanese mispronounces words at the semantic level. Resolving pitch accent demands inference infrastructure built for prosodic control, not a chain of providers each adding latency.
Strict syllables, no clusters
English tolerates heavy consonant clusters[1]: "strengths" stacks multiple consonants around a single vowel. Japanese syllable structure is almost exclusively CV[2]: one consonant, one vowel, with only /N/ or a geminate allowed as a coda. When Japanese absorbs "strike," it becomes /sɯ.to.ɾa.i.kɯ/[3], padding each consonant with a vowel to maintain the CV pattern. TTS architectures built around English phonotactics produce illegal syllable shapes or unnatural epenthetic pauses. Accurate Japanese synthesis needs models that enforce CV constraints natively, with inference co-located alongside audio processing so syllable boundaries stay clean.