At a glance
Agents
Cartesia’s hosted Line voice agents are billed per minute in US dollars. This does not affect your credit balance.Text-to-speech
Standard TTS costs approximately 1 credit per character. The exact number of credits can vary slightly due to transcript pre-processing. This applies to every TTS endpoint:/tts/bytes, /tts/sse, and /tts/websocket.
TTS with a Pro Voice Clone
Generating speech with a Pro Voice Clone costs approximately 1.5 credits per character, 50% more than standard TTS, because it runs on a bespoke model fine-tuned to your data. This does not apply to Instant Voice Clones, which are billed at the standard rate.Speech-to-text
STT pricing depends on the model and whether you use the batch or realtime endpoint. Silence is also included, even if no transcript is produced.Pro Voice Clone Fine-Tuning
Creating a Pro Voice Clone fine-tunes a model on your data via/fine-tunes/create and costs 1,000,000 credits.
You’re only charged when training succeeds. Pro Voice Clones are pinned to the base model they were trained on, so retraining on a new base model or new data costs another 1,000,000 credits.
Infill
Infill generates audio that bridges two existing clips. Each request costs a fixed 300 credits, plus the standard TTS rate applied to the infill transcript.Voice changer
Voice changer converts input audio into a target voice. It costs 15 credits per second of input audio on both/voice-changer/bytes and /voice-changer/sse.