Short answer: Retell AI is for teams that build voice agents to answer and make calls at scale, usually in a contact centre. It has a no-code studio and an API, and bills per connected minute. OsmO is for a person who wants ChatGPT, Claude or another AI app to make a call for them. A business automating its phone lines should look at Retell; someone running errands should use OsmO.
Retell listed voice agents at $0.07 to $0.31 a minute on 13 November 2026, with $10 in free credits.
Retell bills only connected calls, but keeps billing during silence and hold.
OsmO charges 3 credits per answered call however long it lasts, including hold time.
OsmO needs no agent design: add it to your AI app and ask.
How it works
- Sign in with your mobile numberYou get 50 free credits. Nothing to pay.
- Add OsmO to ChatGPTChatGPT, Claude, Grok and other apps that take connectors.
- Ask it to callOsmO calls, talks, and tells you what was said.
The full guide
What Retell is built for
Retell's site describes a platform for building, testing and deploying voice agents that answer and make phone calls and take action in a company's systems. Its examples are contact centres in healthcare, insurance, retail, travel and similar fields. Customer-experience teams design agents in a no-code studio, and developers extend them with APIs and SDKs. Retell lists SOC 2, HIPAA, GDPR and ISO 27001 on its site.
OsmO For my AI is a single, ready-made calling agent that any person can use from their AI app. You do not design it; you just ask it to call.
| Retell AI | OsmO For my AI | |
|---|---|---|
| Main user | Contact centres and the teams that build for them | A person using an AI app |
| Inbound and outbound | Both, plus batch campaigns | Outbound calls to businesses |
| Pricing | $0.07 to $0.31 per minute, pay as you go | 3 credits per answered call |
| Hold time | Billed (billing continues during silence and hold) | Included in the 3 credits |
| Free to start | $10 in credits, 20 free concurrent calls | 50 credits, about 16 answered calls |
| Phone numbers | Retell numbers at $2 a month | Included |
When Retell is the better fit
Retell makes sense when you run the phone line: an inbound support agent, an appointment line, an outbound reminder campaign. You get control over the model, the voice and the integrations, analytics on every call, and enterprise options such as custom SSO and a dedicated server.
When OsmO is the better fit
When you are the caller, not the company. Ringing a clinic to move an appointment or asking a shop to hold an item does not need an agent studio. OsmO places the call from the AI app you already use and keeps the cost flat per call, so a long hold queue does not add to the bill.
- Add OsmO to ChatGPT, Claude, Grok or another AI app that takes connectors.
- Sign in with your mobile number and the texted code.
- Ask for the call in plain words, with the business and your question.
- Read the answer in your chat.
What it costs
OsmO For my AI starts with 50 free credits when you sign in with your mobile number, with no card. An answered call uses 3 credits however long it lasts, and a call nobody answers is free, so the free credits cover about 16 answered calls. When they run out you can keep calling from the OsmO app.
The bottom line
If you are deciding for a company's phone lines, compare Retell with other contact-centre platforms on model choice, integrations, analytics and compliance; OsmO does not belong on that list. If you are deciding for yourself or a small team that keeps putting off calls, OsmO is the lighter option: no agent to design, no number to rent, no per-minute bill for hold music, and a free allowance large enough to see whether it suits you.
Where OsmO works
You can sign in with a mobile number from the United States, Canada, the United Kingdom or Australia (India too), and calls are placed from the OsmO number for your country. OsmO calls listed businesses in your own country, such as shops, clinics, restaurants and offices, and toll-free helplines. With the free web credits it does not call personal numbers; with the OsmO app it can also call your saved contacts.
Questions people ask
Is OsmO an alternative to Retell for my business's phone line?
Not for building one. OsmO For my AI places calls to businesses on your behalf. If you need an agent that answers your company's calls, a platform like Retell fits that job.
Does a long hold cost more with OsmO?
No. An answered call uses 3 credits whatever its length.
Sources
Checked November 13, 2026. Vendors change their products often; follow the links for the current version.
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- OsmO vs Synthflow: what is the difference?Enterprise voice agents on annual contracts vs pay-per-call from your AI app.Read ›
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