Simple, transparent pricing
One subscription for Proso (web) and Lectrice (desktop): managed voices, premium voices, and one shared credit pool.
Checkout is not yet available in this deployment. You can install Proso and configure BYOK or your own synthesis host.
Prices are in USD. Managed allowances are credits, not a fixed character count: OpenAI uses 1 credit per character, ElevenLabs 3, and Groq 0.5, rounded up per request. Cartesia is BYOK-only. BYOK does not spend managed credits.
The free tier is genuinely useful — word-level highlighting and BYOK support with no account. Pay only when you want the managed service instead of your own provider key.
- Word-level highlighting
- Smart text extraction
- Speed control
- Paragraph navigation
- BYOK — your own key from a supported provider
- One subscription for Proso and Lectrice
- Managed voices
- Premium voices
- Priority support
- Everything in Free
- One subscription for Proso and Lectrice
- 500,000 managed credits per month
- Managed voices
- Premium voices
- Priority support
- Everything in Pro
- One subscription for Proso and Lectrice
- 2,000,000 managed credits per month
- Managed voices
- Premium voices
- Priority support
Custom licensing
Need a custom deployment, or commercial terms beyond the standard tiers? We offer flexible licensing for businesses of all sizes.
Contact UsBring Your Own Key (BYOK)
BYOK is available on every tier without a Proso subscription. Your provider may charge for synthesis. Keys are stored in your browser; for requests routed through Proso, the server uses the key for that request without retaining it.
- OpenAI — High-quality voices with natural intonation
- ElevenLabs — Ultra-realistic AI voices with word timing
- Groq — Blazing-fast inference at low cost
- Cartesia — Low-latency streaming voices
Frequently Asked Questions
What happens when I run out of credits?
When your managed credits run out, managed voices pause until your next allocation. You can keep listening with your own API key (BYOK) on any tier — it never spends managed credits.
Can I use my own API keys?
Yes, on every tier, including Free. Proso charges no subscription fee for BYOK; your provider may charge for usage. Bring your own OpenAI, ElevenLabs, Groq, or Cartesia API key and use premium voices without spending any managed credits. Your keys are cached locally in your browser and securely forwarded through our server when you play audio. Keys are used for one request and immediately discarded — never logged or stored.
How do I install the extension?
Install Proso from Mozilla Add-ons in Firefox 109 or later. Before listening, configure your provider API key, a synthesis host you operate, or an eligible managed plan.
What's your refund policy?
Full refund within 7 days for annual plans, no questions asked. Monthly plans are prorated — you'll receive a refund for the unused portion of your billing period.
Do managed credits carry over?
No — unused managed credits do not carry into the next billing cycle. Your full allocation is available until the cycle ends.