> ## Documentation Index > Fetch the complete documentation index at: https://docs.cartesia.ai/llms.txt > Use this file to discover all available pages before exploring further. # Deprecated Models On June 1, 2026, several models, snapshots, and languages were sunsetted. Migrate to `sonic-3.5` for improved naturalness, 42-language support, and fine-grained controls. ## Sunsetted models Sunsetted models will start to error. See this example error response: ```json theme={null} { "error_code": "model_sunsetted", "message": "The requested model has been sunsetted and is no longer available.", "title": "Model sunsetted", "request_id": "897525c5-7bbe-4919-a801-95170b472373" } ``` ### Fully sunsetted models These models stopped serving requests on June 1, 2026. | Model | Snapshots affected | Sunsetted languages | | -------------------- | ------------------------ | ------------------- | | `sonic` | All | All | | `sonic-english` | — | All | | `sonic-multilingual` | — | All | | `sonic-2` | `sonic-2-2025-03-07` | All | | `sonic-turbo` | `sonic-turbo-2025-03-07` | All | ### Partially sunsetted models These models will continue to serve a reduced set of languages. The languages listed below were sunsetted on June 1, 2026. | Model | Snapshots affected | Sunsetted languages | | ------------- | ---------------------------------------------------------------- | -------------------------- | | `sonic-2` | `sonic-2-2025-04-16`, `sonic-2-2025-05-08`, `sonic-2-2025-06-11` | it, nl, pl, ru, sv, tr, hi | | `sonic-turbo` | `sonic-turbo-2025-06-04` | it, nl, pl, ru, sv, tr | ## Stable offerings The following models remain: | Model | Snapshots | Supported Languages | | ------------- | ---------------------------------------------------------------- | ----------------------------------------------------------------------------------- | | `sonic-3.5` | All | 42 languages — [full list](/build-with-cartesia/tts-models/latest#language-support) | | `sonic-3` | All | 42 languages — [full list](/build-with-cartesia/tts-models/older-models#sonic-3) | | `sonic-2` | `sonic-2-2025-04-16`, `sonic-2-2025-05-08`, `sonic-2-2025-06-11` | en, de, es, fr, ja, ko, pt, zh | | `sonic-turbo` | `sonic-turbo-2025-06-04` | en, de, es, fr, ja, ko, pt, zh, hi | ## Breaking API changes These endpoints were sunsetted on June 1, 2026. | Breaking | Replacement | | ----------------------------------------------------------------------- | ---------------------------------------------------------------- | | Voice Embedding: `POST /voices/clone/clip` | [Clone Voice](/api-reference/voices/clone): `POST /voices/clone` | | [Mix Voices](/2024-11-13/api-reference/voices/mix): `POST /voices/mix` | — | | [Create Voice](/2024-11-13/api-reference/voices/create): `POST /voices` | [Clone Voice](/api-reference/voices/clone): `POST /voices/clone` | These endpoints stopped accepting voice embeddings on June 1, 2026. | Endpoint | Breaking | Replacement | | ----------------------------------------------------------------- | ------------------------------ | ----------------------- | | [TTS (bytes)](/api-reference/tts/bytes): `POST /tts/bytes` | `"voice":{"mode":"embedding"}` | `"voice":{"mode":"id"}` | | [TTS (SSE)](/api-reference/tts/sse): `POST /tts/sse` | `"voice":{"mode":"embedding"}` | `"voice":{"mode":"id"}` | | [TTS (WebSocket)](/api-reference/tts/websocket): `/tts/websocket` | `"voice":{"mode":"embedding"}` | `"voice":{"mode":"id"}` | ### API Migration Guides You can move to our [Clone Voice API](/api-reference/voices/clone) or use our [web UI](https://play.cartesia.ai/voices/create/clone) to create voices from 3–10 seconds of source audio. Here is an example using the Cartesia SDK: ```python theme={null} your_api_key: str = "" client = Cartesia(api_key=your_api_key) print("Cloning a voice") with open("3 to 10 seconds of source audio.wav", mode="rb") as f: voice = client.voices.clone( clip=f, # this must match the source audio language="en", name="My Voice", mode="similarity", ) print(f"Cloned voice {voice.id}") print("Generating audio...") generated_audio = client.tts.bytes( # voice embeddings will not work after June 1, 2026! voice={"mode": "id", "id": voice.id}, model_id="sonic-3.5", transcript="Hello from Cartesia!", language="en", output_format={ "container": "wav", "encoding": "pcm_f32le", "sample_rate": 44100 }, ) ``` If you are currently making generation requests with voice embeddings like this: ```json theme={null} { "voice": { "mode": "embedding", "embedding": [1, 2, ..., 3, 4] }, "model_id": "sonic-2", // ... } ``` You will need to switch to using voice IDs like this: ```json theme={null} { "voice": { "mode": "id", "id": "e07c00bc-4134-4eae-9ea4-1a55fb45746b" }, "model_id": "sonic-2", // ... } ``` #### Don't have a voice ID? ##### Check out the voice library Our featured voices have all gone through rigorous evaluations and are ready to use in production. Check them out at [play.cartesia.ai/voices](https://play.cartesia.ai/voices) and copy the ID of any voice you'd like to use. ##### Clone a voice If you have source audio, create a cloned voice via the [playground](https://play.cartesia.ai/voices/create/clone) or the [API](/api-reference/voices/clone). Cloning returns a voice ID you can use immediately. ## Why are we doing this? Since the launch of Sonic 3, we've made improvements across pacing, prosody, and naturalness; the vast majority of our customers have migrated to these models with great success. In order to increase our capacity, availability, and serving performance, we have to discontinue our oldest models. Additionally, our newer models have evolved beyond voice embeddings in order to sound more natural. The parts of our API that accept voice embeddings cannot be made forward-compatible. Migrating to voice IDs will allow us to continue to improve both our models and your voices in tandem. If you have questions, reach out to [support@cartesia.ai](mailto:support@cartesia.ai).