xAI's audio API pricing is quite interesting, with batch STT costing only $0.1 per hour, while TTS is actually more expensive at $4.2 per million characters. Is this premium for emotional label values?

ME News reports that xAI has launched two standalone audio APIs: Grok STT and Grok TTS, originating from the same audio stack, supporting Grok Voice, Tesla in-car systems, and Starlink customer service, among others. STT offers REST batch transcription and WebSocket real-time streaming, with word-level timestamps, speaker separation, multi-channel support, and inverse text normalization, covering over 25 languages; TTS supports inline tags for emotion and prosody. They also published WER comparisons, with Grok leading in multiple scenarios, but no third-party re-evaluation has been conducted yet. Pricing: STT batch processing at $0.10 per hour, streaming at $0.20 per hour, TTS at $4.20 per million characters.