Credits & Pricing
Understand the shared credit system, Text-to-Speech billing rates, and the developer discount.
Sonna runs on a unified credit system. Your credit balance is shared across the Sonna app (Speech, Image, Video, Music) and the REST API, synced instantly across web, Android, and API. The developer API itself is Text-to-Speech only — the pricing below is what the API bills.
10% Developer API Discount
Developer Benefit: Authenticating REST API requests with an API Key consumes exactly 10% fewer credits than generating via the Web Studio or Android UI. This discount applies to all Text-to-Speech generations.
Subscription Plans & Access
Every account — Free, Pro, and Max — can call the REST API. Free accounts are limited to Google Cloud TTS voices; ElevenLabs and Gemini voices require a Pro/Max subscription or PAYG credits.
For full plan allowances, PAYG top-ups, and cross-platform billing details, see Credits & Plans. To query your live balance programmatically, use the Credits & Subscription API.
Who can use the API
API keys can only be minted by paying users (active Pro/Max subscription OR a positive PAYG balance). See API Authentication.
Text-to-Speech Pricing
Credits are deducted upfront when synthesis starts and refunded automatically on failure (see Errors & Refunds).
TTS is billed per character, but rates are shown here per 1,000 characters for readability. Billing is pro-rated to the exact character count (minimum 1 character).
| Provider | Model | Cost per 1,000 chars | Minimum Charge |
|---|---|---|---|
| ElevenLabs | Eleven v3 (Default) | 2,100 credits | 1 char |
| ElevenLabs | Multilingual v2 | 2,100 credits | 1 char |
| ElevenLabs | Flash v2.5 | 1,050 credits | 1 char |
| Google Cloud | Neural2 / Wavenet | 500 credits | 1 char |
| Google Cloud | Google TTS (Free Plan) | 0 credits | 1 char |
| Gemini | Gemini 2.5 Flash | 700 credits | 1 char |
| Gemini | Gemini 2.5 Pro | 1,050 credits | 1 char |
Pro-rated per character
The "per 1,000 chars" figure is for easy comparison. You're charged for the exact number of characters — e.g. a 500-character script on Eleven v3 costs 1,050 credits, not 2,100.