Kotoba TTS v2

Kotoba STT v1

Transcribe audio or video clips up to 120 seconds in Japanese, English, Korean, Mandarin, Taiwanese Mandarin, Hong Kong Cantonese, or Spanish. Requires an explicit spoken language; no language detection or translation. Optional word timestamps and beta speaker diarization.

Qwen Audio 3.1 TTS Plus

High-quality multilingual speech synthesis for narration, dubbing, brand voices, and character performance. Four preset voices support instruction-guided emotion, tone, and persona, plus SSML and expressive tags. Returns MP3, WAV, or PCM audio after generation completes. Optional API word timestamps return JSON with base64 audio. Billed by measured characters. NanoGPT accepts up to 20,000 characters per request; this is a transport limit.

Voxtral TTS 3

Generate multilingual speech with preset voices or a per-request MP3 or WAV voice reference. Supports inline emotion and pace tags, pronunciation hints, and MP3, WAV, PCM, FLAC, or Opus output. Up to 4,000 input characters; returns completed audio.

Qwen Audio 3.1 TTS Flash

Speech synthesis with four multilingual voices in Singapore. Supports Japanese, Korean, French, German, Portuguese, Italian, Vietnamese, and Indonesian, plus eight Chinese dialects. Returns MP3, WAV, or PCM audio after generation completes. Billed by measured input and output tokens; character-based previews are estimates.

Gemini 3.8 Flash TTS

Accepts compatible input turns: one turn for narration or exactly two distinct voices for multi-turn dialogue (up to 100 turns and 8,192 normalized input bytes). Expressive narration and two-speaker dialogue with 30 voices, delivery instructions, and inline vocal events. Returns WAV audio. Billed by exact spoken characters with no per-request minimum; instructions are not billed. The complete input is limited to 8,192 tokens.

Qwen Audio 3.0 TTS Flash

Fast multilingual text-to-speech with a broad set of voices and explicit language control.