- 42 languages out of the box — English, Hindi, Spanish, French, German, Japanese, Hebrew, and 35 more, each at native quality
- Expressive, conversational delivery — strong pacing and real emotional range, tuned for support and agent transcripts
- Clean audio across every language and voice, with no artifacts to edit out
- Alphanumerics that sound right — order numbers, phone numbers, IDs, and emails spoken naturally in every language, no preprocessing
- Context-aware English pronunciation — heteronyms like read, bass, and bow land correctly from the surrounding words
Voice selection
Choosing voices that work best for your use case is key to getting the best performance out of Sonic 3.5. The recommendations below are starting points carried over from Sonic 3 — they work as-is on Sonic 3.5. We’ll be publishing 3.5-specific picks in the coming weeks. For voice agents: We’ve found stable, realistic voices work better for voice agents. Example American English voices include:- Katie (ID:
f786b574-daa5-4673-aa0c-cbe3e8534c02) - Jameson (ID:
a5136bf9-224c-4d76-b823-52bd5efcffcc)
Language support
Sonic 3.5 supports the following languages:English (en) | French (fr) | German (de) | Spanish (es) |
Portuguese (pt) | Chinese (zh) | Japanese (ja) | Hindi (hi) |
Italian (it) | Korean (ko) | Dutch (nl) | Polish (pl) |
Russian (ru) | Swedish (sv) | Turkish (tr) | Tagalog (tl) |
Bulgarian (bg) | Romanian (ro) | Arabic (ar) | Czech (cs) |
Greek (el) | Finnish (fi) | Croatian (hr) | Malay (ms) |
Slovak (sk) | Danish (da) | Tamil (ta) | Ukrainian (uk) |
Hungarian (hu) | Norwegian (no) | Vietnamese (vi) | Bengali (bn) |
Thai (th) | Hebrew (he) | Georgian (ka) | Indonesian (id) |
Telugu (te) | Gujarati (gu) | Kannada (kn) | Malayalam (ml) |
Marathi (mr) | Punjabi (pa) |
Model snapshots
| Snapshot | Release Date | Languages | Status |
|---|---|---|---|
sonic-3.5-2026-05-04 | May 4, 2026 | en, de, es, fr, ja, pt, zh, hi, ko, it, nl, pl, ru, sv, tr, tl, bg, ro, ar, cs, el, fi, hr, ms, sk, da, ta, uk, hu, no, vi, bn, th, he, ka, id, te, gu, kn, ml, mr, pa | Stable |
Continuous updates
Using the model IDsonic-3.5 in your API calls will automatically keep you up to date with the most recent stable snapshot of the model.
If pinning a specific version is important for your use case, we recommend using a dated version in production.
For testing our latest capabilities, we recommend using sonic-latest, which is a non-snapshotted version. sonic-latest can be updated with no notice, and is not recommended for production.
model_id | Model update behavior | Recommended for |
|---|---|---|
sonic-3.5-YYYY-MM-DD | Snapshotted, will never change | Customers who want to run internal evals before any updates |
sonic-3.5 | Will be updated to point to the most recent stable snapshot | Customers who want stable releases, but want to be up-to-date with the recent capabilities |
sonic-latest | Will always be updated to our latest beta releases | Testing purposes |
Switching from Sonic 3?
If you’re already using Sonic 3, see Migrating from Sonic 3 to Sonic 3.5 for what’s new and what to know before you switch.Older Models
For information onsonic-3, sonic-2, sonic-turbo, and sonic, see our page on Older TTS Models.
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