| Field | Speechify API | Deepgram |
|---|---|---|
| Type | Ongoing free tier · renewing-quota | Trial credit · trial-credit |
| What's free | 50,000 characters/month TTS (hard cap) + 60 min/month voice agents | $200 free credit on signup (no card, no expiration) — Nova speech-to-text and Aura text-to-speech at pay-as-you-go rates |
| Rate limits | 3 concurrent calls; hard cap pauses at the limit (no overages) | STT pre-recorded up to 50 concurrent; STT streaming up to 150; TTS REST up to 15; TTS streaming up to 45 |
| Expires | no expiry | no expiry |
| The catch | Commercial use is allowed on the free tier. No credit card required. Hard monthly cap that pauses at the limit. | No card and no expiration on the credit. Data catch: the Model Improvement Program is opt-OUT — send mip_opt_out=true per request to keep your data out of training. Native REST/WebSocket API, not OpenAI-compatible. |
| Credit card | not required | not required |
| Phone verification | not required | not required |
| Commercial use | allowed | allowed |
| OpenAI-compatible | no | no |
| Modalities | audio | audio |
| Free models (sample) | no sample | no sample |
| Official docs | speechify.ai/pricing | deepgram.com/pricing |
| Last verified | 2026-08-14 | 2026-10-08 |