Call every customer, without picking up a phone
Type a message and Hellio speaks it in a natural voice, or upload your own recording, then broadcast the call to one recipient or thousands. No apps, no data plan, no reading required. One API, the same platform you already use for SMS and WhatsApp.
Pay per second of audio, per recipient. See the exact cost before you send.
YourClinic
Voice call · 00:14
What you can build
Everything you need for voice
From a single verification call to a broadcast reaching thousands, all through the same Hellio API and dashboard.
Text-to-speech
Type your message and we synthesize it into natural-sounding speech. Pick from six voices and preview the audio before you send.
Your own recordings
Upload an MP3 or WAV, or point us at an audio URL, and we play it to every recipient exactly as recorded.
Broadcast at scale
Send to a pasted list, an imported file or your saved contact groups. One campaign can reach thousands of numbers.
Schedule campaigns
Queue a broadcast now or schedule it for later, and Hellio places the calls at the right moment.
Voice OTP
Deliver one-time passwords as a spoken call, on their own or as an automatic fallback when an SMS code does not land.
Resilient delivery
Calls route through multiple carrier gateways with automatic failover, and per-call delivery reports flow back to your dashboard.
How it works
From message to ringing phones in three steps
Write or upload
Type the message you want spoken and choose a voice, or upload a pre-recorded MP3 or WAV file.
Pick recipients
Paste numbers, import a file or select a contact group. We show the audio length and the exact cost before anything is sent.
We place the calls
Hellio dials every recipient, plays your audio, and reports each call back so you can see who was reached.
{
"recipients": ["233241234567", "233551234567"],
"text": "Hello! Your order 1042 is ready for pickup.",
"voice": "nova"
}Use cases
When a call works better than a text
A ringing phone gets answered. Voice reaches feature phones, people on the move, and customers who cannot read an SMS.
Voice OTP and 2FA
Read verification codes aloud over a call. Ideal as a fallback when SMS is delayed, filtered or unavailable, so the code always gets through.
Alerts and reminders
Appointment reminders, payment-due notices, outage alerts and emergency broadcasts that demand immediate attention.
Campaigns and announcements
Product launches, event invitations, community announcements and political outreach, delivered in your own recorded voice.
Reach everyone
No smartphone, no data and no literacy required. A voice call in a familiar voice reaches audiences SMS and email never will.
Pay only for the audio you play
Voice broadcasts are billed per second of audio, per recipient, from the same wallet as your SMS and WhatsApp traffic. A 12-second reminder costs exactly 12 seconds worth, and you see the estimate before you confirm the send.
Same wallet, dashboard and API
Send from the Voice Broadcast screen in your dashboard or call the API with the token you already have. Campaign history, per-call delivery reports and spend all live next to your other channels.
Give your messages a voice
Create an account, type your first message, and hear it ring through in minutes.