Spokestack - 2026 Pricing, Features, Reviews & Alternatives

Spokestack is a unified API and open-source library suite that delivers a full voice stack for mobile, web, and embedded software. The platform consolidates wake word detection, keyword recognition, automatic speech recognition (ASR), natural language understanding (NLU), and text-to-speech (TTS) under a single modular API, with SDKs available for Android, iOS, React Native, Node, and Python. Deployment is hybrid: cloud-based hosted services power TTS, ASR, and model hosting, while NLU, wake word, and keyword models can run entirely on-device via native open-source libraries, supporting offline operation and keeping audio data off third-party servers.

The configurable Speech Pipeline gives developers granular control over how voice activity detection (VAD), wake word, and ASR components are combined. A drop-in mobile UI widget, Spokestack Tray, handles voice interaction flows with minimal code. TTS synthesis supports plain text, SSML, and Speech Markdown, and includes custom brand voice creation and personal voice model training from as little as five minutes of recorded audio. Deep learning-based NLU models handle intent and slot classification and are deployable on-device or as a hosted web service. AutoML tooling in a point-and-click web interface allows teams without machine learning expertise to train custom wake word, keyword, and TTS models.

Spokestack targets software developers and companies across the full maturity spectrum: a free tier covers hobbyists and individual creators with pre-trained TTS, wake word, keyword, and NLU models; a Maker subscription serves prototypers and startups building MVPs; and an Enterprise plan provides custom pricing with unmetered cloud API access and custom voice model support. The open-source native libraries are released under the Apache License v2.0.