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Siel
SMS API and CPaaS platform for OTPs and alerts
- Community votes
- 0
- DR by Ahrefs
- 0 no change since last check
Ahrefs Domain Rating benchmarked 14 Nov 2026, rebuilt 14 Nov 2026.
Siel is a CPaaS platform for SMS messaging that sends OTPs, alerts and bulk SMS campaigns via REST API, SMPP or web app, with every route tested on real phones.
What it is
Siel is a communications platform as a service (CPaaS) for SMS operated by Siel Labs. It enables businesses to send one-time passwords, alerts and bulk SMS campaigns through a REST API, SMPP protocol or web application. The platform tests every route against real phones and monitors live traffic receipts to ensure delivery receipts are trustworthy. Customers see the price of each message before sending, receive signed delivery webhooks, and can set fraud protection limits on spending, countries and OTP codes. The platform offers a web app for non-technical users, campaign management with CSV imports, mobile apps for iOS and Android, and detailed analytics showing delivery rates, timing and spending.
What it is built with
- REST API and SMPP 3.4 protocol support
- Routes tested on real phones
- Campaign management with CSV import
- OTP by SMS and Telegram
- Fraud protection with spending and OTP limits
- Real-time delivery analytics
- Mobile apps for iOS and Android
- Public pricing by country
- Message price shown before sending
Pricing
Pricing model: Paid
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Siel metrics
| Metric | Value |
|---|---|
| Domain Rating | 0 no change since last check |
| Trust Flow | 0 no change since last check |
| Citation Flow | 0 no change since last check |
| Referring domains | 0 no change since last check |
| External backlinks | 0 no change since last check |
Ahrefs Domain Rating benchmarked 14 Nov 2026, rebuilt 14 Nov 2026. Majestic benchmarked 14 Nov 2026, rebuilt 14 Nov 2026. Link data built by Majestic. Trust Flow, Citation Flow and Topical Trust Flow are trademarks of Majestic-12 Ltd.
Siel domain build sheet
Open the build sheet
| Domain age | 15 days |
|---|---|
| Registered | |
| Expires | |
| Registrar | Cloudflare, Inc. |
| DNSSEC | Not signed |
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Questions from the bench
- What is Siel?
- Siel is a CPaaS platform for SMS. Businesses send OTPs, alerts and bulk SMS campaigns with a REST API, SMPP or the web app, and see the receipt, price and timing of every message. OTP codes can also go by Telegram.
- How is Siel priced?
- Pricing is per message part from a prepaid balance with no monthly fee, no minimum and no contract. Each country has a price on the public price list, and the API tells you the price of each message when it accepts it.
- How do you know a message was really delivered?
- Operators send a receipt for each part, and Siel tests routes with real phones and watches receipts on live traffic. Routes whose receipts do not match what phones receive stop counting in quality routing.
- Can I connect over SMPP instead of the API?
- Yes. SMPP is turned on for your account and you create a login in the web app and bind with SMPP 3.4 over TLS. Submits go through the same validation, pricing and routing as the API.
- How do you stop fraud and SMS pumping on my account?
- Limits can be set in the web app for the countries the account sends to, daily and monthly spending limits, codes per number and per hour, and links are checked against phishing lists. Whatever a limit stops is not sent and not charged.
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