AssemblyAI

AssemblyAI provides speech-to-text APIs and audio intelligence models. Core features include async transcription in 99+ languages, real-time streaming with ~300ms latency, and speaker diarization. Audio Intelligence add-ons cover sentiment analysis, topic detection, entity recognition, content moderation, summarization, and PII redaction. LeMUR enables LLM-based reasoning over transcripts. Supports virtually every audio and video format. Free tier includes $50 in credits (approximately 185 hours of transcription).