{"schema":"postcutoff/model@1","as_of":"2026-11-13T13:49:00+01:00","url":"https://postcutoff.com/m/cartesia-sonic-3-6/","md":"https://postcutoff.com/m/cartesia-sonic-3-6/index.md","disclosure":{"written_by":"AI agents (Claude Opus 5.5 in Claude Code)","editor":"human editor","policy":"https://postcutoff.com/about/"},"license":null,"id":"cartesia-sonic-3-6","name":"Cartesia Sonic-3.6","org":"Cartesia","family":"Sonic","released":"2026-08-27","status":"current","type":"audio/speech","modality_in":["text"],"modality_out":["audio"],"open_weights":false,"model_license":"proprietary","context_window":null,"max_output":null,"knowledge_cutoff":null,"pricing":{"per_1k_characters":0.037,"unit":"approx., derived: ~1 credit per character; Scale plan $299/mo for 8M credits (Startup $49 for 1.25M ≈ $0.039/1K). Artificial Analysis lists $49 per 1M chars","source":"https://cartesia.ai/pricing"},"price_line":"$0.037 per 1K characters","access":[{"provider":"Cartesia API","model_id":"sonic-3.6","endpoint":"https://api.cartesia.ai/tts/bytes (also /tts/sse and WebSocket)","docs":"https://docs.cartesia.ai/build-with-cartesia/tts-models/latest"},{"provider":"Cartesia API (pinned snapshot)","model_id":"sonic-3.6-2026-08-27","endpoint":"https://api.cartesia.ai/tts/bytes"},{"provider":"Web app","url":"https://play.cartesia.ai"}],"capabilities":[{"name":"State-space-model TTS, sub-90 ms","detail":"Built on state space models (SSMs); replies in under 90 ms and generates ~132 chars/s (nearly 2x Sonic 3 Conversational). Listeners preferred it over Sonic-3.5 in up to 93% of blind tests across 15 locales.","first":false,"discovered":"launch","source":"https://www.cartesia.ai/blog/sonic-3.6"},{"name":"44 languages with instant cloning","detail":"Adds Odia and Urdu to Sonic-3.5's 42 languages; instant voice cloning; locale-aware reading of dates/numbers; confirmation codes and heteronyms without preprocessing.","first":false,"discovered":"launch","source":"https://docs.cartesia.ai/build-with-cartesia/tts-models/latest"},{"name":"Multilingual Voices (one voice, 25 languages)","detail":"Launched 2026-09-23 on Sonic-3.6: 50+ library voices each speak up to 25 languages natively, and custom clones from ~10 s of audio carry their identity across languages via a `locale` parameter; native speakers rate each variant for accent and localization of dates, numbers and currency.","first":false,"discovered":"later","source":"https://www.cartesia.ai/blog/multilingual-voices"},{"name":"Top-2 on Artificial Analysis Speech Arena","detail":"Ranked #1 (Elo ~1279) on the Artificial Analysis TTS leaderboard in mid/late Sept 2026, then #2 (Elo 1275) behind Eleven v4 after 2026-09-28.","first":false,"discovered":"later","source":"https://artificialanalysis.ai/text-to-speech/leaderboard/provider-voice"}],"entry":"2026-08-27-cartesia-sonic-3-6","notes":"Beta 2026-08-17, GA snapshot 2026-08-27. Header `Cartesia-Version: 2026-08-14`. Fully backwards compatible with Sonic-3.5 (snapshot 2026-05-04, which led AA's Controlled Voice Arena at its 2026-07-08 launch with 1,122 Elo). Scored 0.840 (#5) on Hume's Real-World VoiceEQ leaderboard (2026-09-24). sonic-3 snapshots (2025-10-27, 2026-01-12), sonic-2 and sonic-turbo sunset 2026-10-20. `sonic-preview` = beta channel; `sonic-latest` alias deprecated. Exact per-character USD price is plan-dependent (credits); figure above is derived. Also on AWS SageMaker JumpStart (Sonic 3, Feb 2026).","verified":"2026-09-29","body_md":"Cartesia's flagship low-latency TTS for voice agents.\n\n```bash\ncurl -X POST https://api.cartesia.ai/tts/bytes -H \"Authorization: Bearer $CARTESIA_API_KEY\" -H \"Cartesia-Version: 2026-08-14\" \\\n  -H \"Content-Type: application/json\" -d '{\"model_id\":\"sonic-3.6\",\"transcript\":\"Your code is 4 8 1 5.\",\"voice\":{\"mode\":\"id\",\"id\":\"<voice_id>\"},\"output_format\":{\"container\":\"wav\",\"encoding\":\"pcm_s16le\",\"sample_rate\":44100}}' -o out.wav\n```\n\nSources: https://docs.cartesia.ai/build-with-cartesia/tts-models/latest , https://docs.cartesia.ai/build-with-cartesia/tts-models/older-models , https://www.cartesia.ai/blog/sonic-3.6","page_url":"https://postcutoff.com/m/cartesia-sonic-3-6/","standing":{"kind":"speech and audio","newer_count":31,"newer":[{"id":"nemotron-3-5-transcribe","name":"NVIDIA Nemotron 3.5 Transcribe (30B-A4B)","org":"NVIDIA","released":"2026-10-28","page_url":"https://postcutoff.com/m/nemotron-3-5-transcribe/"},{"id":"hy-simulmt-30b-a3b","name":"Hy-SimulMT-30B-A3B","org":"Tencent","released":"2026-10-22","page_url":"https://postcutoff.com/m/hy-simulmt-30b-a3b/"},{"id":"eleven-realtime-v1-max","name":"Eleven Realtime v1 Max / Mini","org":"ElevenLabs","released":"2026-10-20","page_url":"https://postcutoff.com/m/eleven-realtime-v1-max/"},{"id":"voxtral-mini-transcribe-3","name":"Voxtral Mini Transcribe 3 (+ Mini Transcribe Realtime 3)","org":"Mistral AI","released":"2026-10-20","page_url":"https://postcutoff.com/m/voxtral-mini-transcribe-3/"},{"id":"voxtral-small-transcribe-3","name":"Voxtral Small Transcribe 3","org":"Mistral AI","released":"2026-10-20","page_url":"https://postcutoff.com/m/voxtral-small-transcribe-3/"}],"before":{"id":"cartesia-ink-2","name":"Cartesia Ink-2 (streaming STT)","org":"Cartesia","released":"2026-07-09","page_url":"https://postcutoff.com/m/cartesia-ink-2/"},"after":null,"weights":"closed","licence":"proprietary","licence_permissive":false,"summary":"Closed weights; access is hosted only."}}