Unreal Speech

Unreal Speech is a text-to-speech API that offers natural-sounding voices, low latency, high uptime, and pricing that scales as your usage grows. You can start with 1 million free characters per month, then take advantage of volume discounts at higher tiers. Unreal Speech has an easy to integrate API with client libraries for many languages. There’s also a live demo on their website which lets you freely test out their TTS with 4 different voices.