Audio APIs — transcription (STT) and synthesis (TTS) — often ship a real free tier or a sizeable one-time credit. The providers below offer free audio/speech access, from a few free hours a month to hundreds of dollars in starting balance.
Check the "catch" on each provider's page: some free speech tiers forbid commercial use or watermark the output.
Top pick — Groq
Lowest-latency inference for open-weight models Details →
17 verified providers
| Provider | Free tier | Rate limits | Gotchas |
|---|---|---|---|
| Google Gemini API (AI Studio) | Gemini 2.5 Flash, 2.5 Flash-Lite, 2.5 Pro (limited), embeddings, TTS models | Varies by model, roughly 5-30 req/min and 20-500 req/day depending on model | no cardno phonecommercial OKOpenAI-compatible |
| Groq | Open-weight models (Llama, Qwen, GPT-OSS) plus Whisper, no credit card required | e.g. llama-3.1-8b-instant: 30 RPM/14.4K RPD/6K TPM/500K TPD; llama-3.3-70b-versatile: 30 RPM/1K RPD/12K TPM/100K TPD; qwen3-32b: 60 RPM/1K RPD/6K TPM/500K TPD; similar for GPT-OSS and Whisper models | no cardphone requiredcommercial OKOpenAI-compatible |
| Cloudflare Workers AI | 10,000 Neurons/day, all account plans | 30+ models: LLMs (Llama, Mistral, DeepSeek, Qwen...), embeddings, image, audio | no cardno phonecommercial OKOpenAI-compatible |
| HuggingFace | Free CPU Basic + ZeroGPU for Spaces; Inference Providers has a monthly credit ($0.10/mo on Free plan, $2.00/mo on PRO/Team/Enterprise) | No RPM/TPM published, only credit amounts | no cardOpenAI-compatible |
| Scaleway Generative APIs | 1,000,000 tokens free + 60 min Whisper transcription; billing starts at token 1,000,001 | Gemma, Llama, Mistral, Qwen | OpenAI-compatible |
| Deepgram | $200 free credit on signup (no card, no expiration) — Nova speech-to-text and Aura text-to-speech at pay-as-you-go rates | STT pre-recorded up to 50 concurrent; STT streaming up to 150; TTS REST up to 15; TTS streaming up to 45 | no cardno phonecommercial OK |
| AssemblyAI | $50 free credit on signup (no card) — pre-recorded & streaming speech-to-text, Speech Understanding, and an OpenAI-compatible LLM Gateway (25+ models) | Free tier: 5 parallel transcriptions; streaming 5 new streams/min; global 20k requests / 5 min | no cardno phonecommercial OKOpenAI-compatible |
| Pollinations.ai | Free hosted image models (Flux, Turbo, Stable Diffusion) via a simple GET URL; also text and audio. No signup required to start | Anonymous ~1 request / 15s; free registration (Seed tier) ~1 request / 5s | no cardno phone |
| Twelve Labs (Marengo Embed) | Free plan: the Marengo Embed API for all input types (video, audio, image, text) at no cost, plus ~600 min indexing | Embed video/audio: 3,000 RPD, 25 RPM; embed text/image: 3,000 RPD, 600 RPM | no card |
| Speechmatics | 3,000 minutes (50 hours)/month speech-to-text + 1,000,000 characters (~20 hrs)/month text-to-speech | 2 concurrent real-time sessions on the free plan | no card |
| Speechify API | 50,000 characters/month TTS (hard cap) + 60 min/month voice agents | 3 concurrent calls; hard cap pauses at the limit (no overages) | no cardno phonecommercial OK |
| Hume AI (Octave TTS) | 10,000 characters/month TTS (~10 minutes) on the Free plan | 15 requests per minute | no cardcommercial OK |
| Unreal Speech | 250,000 characters/month TTS (~6 hours of audio) | Tiered endpoints for different text lengths; specific caps not documented | commercial OK |
| ElevenLabs | 10,000 credits/month shared across Text-to-Speech, Speech-to-Text and more (~10 min TTS/month) | Concurrency tied to the Free plan (not numerically published) | no cardno phoneeval only |
| Sarvam AI | ₹100 in free credits on signup, usable across all APIs including the Sarvam-M chat/LLM API and speech (STT/TTS) | Not published; bounded by the ₹100 credit | OpenAI-compatible |
| Gladia | €50 in free credits on signup for speech-to-text (~80+ hrs pre-recorded or 60+ hrs real-time at current rates) | Not published; bounded by the €50 credit | |
| Rime | 3,000 free TTS minutes for every new account (Starter plan) | Starter: 20 concurrent TTS generations |
FAQ
Is there a free speech-to-text API?
Yes — Groq (Whisper), Cloudflare Workers AI and others offer free STT; several dedicated speech providers also grant a sizeable one-time credit.
Which free speech API is best for production?
Check each provider’s rate limits and whether commercial use is allowed — some free speech tiers are evaluation-only or watermark their output.