Cartesia alternative · Speech APIs
A Cartesia alternative for Hindi text to speech
₹1 is the T1 voice rate. On T1, Mirai phone calling (₹0.30/min) and call insights (₹0.20/min) are optional; T5 includes both. All prices exclude GST.
Mira TTS is a Hindi, English and Hinglish text-to-speech API at ₹1.80 per 1,000 characters, called through OpenAI's speech protocol. Cartesia sells Sonic 3.6 on monthly credit plans, from a free 20K credits to $299 for 8M, where one credit is one character, and lists Hindi among 44 languages with expanded support for Hindi written in Latin script. Choose Cartesia for many languages, voice cloning and WebSocket continuations; choose Mira TTS for code-switched Hindi calls, pay-per-use rupee billing and more concurrency on the entry plan.
No sign-up to look around.
Side by side
Cartesia and Voice Infra
Cartesia's column comes from Cartesia's own public pages, each cell linked to the page it was read from. Ours comes from our price list and docs. Pages change, so check the links before you decide.
| Question | Cartesia | Voice Infra |
|---|---|---|
| Published price | Free: 20K credits/month. Pro $5/month: 100K. Startup $49: 1.25M. Scale $299: 8M. One credit is one character for Sonic; overage $65 (Pro) to $38 (Scale) per 1M credits Source: cartesia.ai | ₹1.80 per 1,000 characters, on pay as you go and on Business (₹50,000/month commitment), before GST |
| Hindi and Hinglish | Sonic 3.6 lists Hindi (hi) among 44 languages, with "expanded support for Hindi transcripts written in Latin script" Source: docs.cartesia.ai | Hindi, English and Hinglish. The voices are Hindi voices that code-switch into English |
| Streaming | Bytes, SSE and WebSocket endpoints all stream; WebSocket adds continuations and many generations per connection Source: docs.cartesia.ai | Raw PCM streams over HTTP as it renders; a WebSocket endpoint keeps one connection open for a whole call |
| Phone-line audio | Raw pcm_mulaw or pcm_alaw at 8 kHz; PCM up to 48 kHz; WAV and MP3 on the bytes endpoint only Source: docs.cartesia.ai | Raw 8 kHz μ-law or A-law; PCM or WAV, 48 kHz by default |
| Concurrent requests | 2 on Free, 3 on Pro, 5 on Startup, 15 on Scale; custom on Enterprise Source: cartesia.ai | 5 on pay as you go, 25 on Business; more on Enterprise |
| API protocol | Cartesia's own API: POST /tts/bytes, POST /tts/sse and a TTS WebSocket Source: docs.cartesia.ai | OpenAI's POST /v1/audio/speech with model mira-tts |
| Data location | The pricing page names no hosting region; DPAs and BAAs are listed on Enterprise Source: cartesia.ai | Audio, speech recognition, TTS and the model run in India (Mumbai, Noida and Delhi). The control plane (workflow orchestration and the API) runs in Europe, off the audio path |
| Try it free | Free plan: 20K credits a month; the commercial use licence starts on Pro Source: cartesia.ai | No sign-up to look around the sandbox; ₹200 of credit once you confirm a work email; clips you play in the console are not charged |
For six platforms in one table, see Voice AI platforms compared.
Which to pick
Which to pick
Choose Cartesia if…
- You need many languages from one voice API. Sonic 3.6 lists 44, including Tamil, Telugu, Bengali, Gujarati, Kannada, Malayalam, Marathi, Punjabi, Odia and Urdu.
- You want to clone a voice. Instant voice cloning starts on the $5 Pro plan and professional voice cloning on the $49 Startup plan.
- Your source text is Hindi in Latin script. Cartesia says Sonic 3.6 has expanded support for Romanised Hindi and better pronunciation of Indian names and places.
- You want word or phoneme timestamps and continuations, where one spoken line arrives over several WebSocket messages as your LLM writes it.
Choose Voice Infra if…
- You want to pay per character in rupees, without a monthly plan: ₹1.80 per 1,000 characters on pay as you go, before GST, from a prepaid wallet whose credit never expires.
- You need more simultaneous requests on the entry plan: 5 on pay as you go and 25 on Business, against 2 on Cartesia's Free plan and 3 on Pro.
- Your code already calls OpenAI's speech endpoint. Ours takes the same request, so the switch is a base URL and a model name.
- You want the speech generated in India, and call transcription and phone agents on the same key.
In detail
A Cartesia alternative for Hindi text to speech: in detail
How do Cartesia and Mira TTS differ?
Cartesia builds Sonic, a fast multilingual speech model, and sells it on monthly credit plans alongside speech to text and a managed agent product. Sonic 3.6 lists 44 languages, Hindi and several other Indian languages among them, and Cartesia says it now handles Hindi written in Latin script and pronounces Indian names and places better than before. Its WebSocket API lets one spoken line arrive in pieces as a language model writes it, with timestamps if you need them.
Mira TTS covers less ground on purpose. It is the voice our own phone agents use, built for Hindi and the Hinglish around it, and it speaks OpenAI’s request shape. You pay per character from a rupee wallet, with no plan to choose.
What does it cost?
Cartesia’s plans bundle credits: 20K free each month, 100K on Pro at $5, 1.25M on Startup at $49 and 8M on Scale at $299, with one credit per character of Sonic speech. Paid plans can run into overage at $65 per million credits on Pro, $45 on Startup and $38 on Scale.
Mira TTS is ₹1.80 per 1,000 characters on pay as you go and on Business, so 10 lakh characters is 1,000 × ₹1.80 = ₹1,800 before GST. Credit never expires, failed or partial requests are not charged, and each response reports what it cost in a header.
Concurrency is where the entry plans differ most. Cartesia allows 2 simultaneous requests on Free, 3 on Pro and 5 on Startup. Our pay-as-you-go plan allows 5 and Business allows 25, which matters once several calls speak at the same moment.
What does switching take?
The endpoint shape changes. Cartesia’s bytes endpoint takes a transcript, a voice ID and an output_format object with container, encoding and sample rate. Ours is OpenAI’s POST /v1/audio/speech with model: "mira-tts", a voice name and a response_format that carries the encoding and rate, such as ulaw_8000 or pcm_16000. For live calls, our WebSocket endpoint plays the role of Cartesia’s: one socket per call, text in as it is written, audio out per sentence, and a cancel message for barge-in.
How should you compare them?
Both say they handle Hindi with English mixed in, so test exactly that. Write lines like the ones your product says, with names, rupee amounts, dates and English product words inside Hindi sentences, and render them on both. If your text arrives in Latin script, include those lines too, since that is where Cartesia says it has improved. Play the clips blind to people who speak Hindi daily, then again over a phone line at 8 kHz. The Hindi TTS comparison lists the other Hindi voices on the market with their published prices.
If you are building a calling agent, our per-minute plans include the voice: ₹1 a minute on T1 with a ₹1,00,000 monthly commitment, ₹3 on T3 with ₹50,000 a month, or ₹5 pay as you go.
By Mirai Minds · Published
Questions
What do 10 lakh characters cost on each?
On Cartesia, 1,000,000 characters is 1,000,000 credits, which fits inside the $49 Startup plan's 1.25M monthly credits; past a plan's credits, overage runs $45 per million on Startup. On Mira TTS it is 1,000 × ₹1.80 = ₹1,800 before GST, with no plan needed. Convert the currency at your own rate.
Can Mira TTS clone my voice?
Custom voices are part of our Enterprise plans; contact us. If you need self-serve cloning today, Cartesia offers instant cloning from the Pro plan.
Does Mira TTS take text as an LLM streams it?
Yes, on the WebSocket endpoint. Send text as your model writes it and audio comes back sentence by sentence, and one message stops a reply when the caller interrupts.
Is Mira TTS ₹1 a minute?
No. ₹1 a minute is the T1 price for a whole phone agent, with a ₹1,00,000 monthly commitment; pay as you go agents are ₹5 a minute. Mira TTS on its own is priced by the character.
Check our column yourself.
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