SEND SMS API
With the Sinch SMS API, accessed through Conversation API, you can programmatically send SMS via a simple POST request and get real-time delivery callbacks. It’s built for low-latency with high-reliability delivery, while clean REST endpoints, official SDKs, and >99.95% uptime help you ship with confidence.
WHY CHOOSE SINCH
Scale with a single API to send SMS to 190+ countries. Developers get clear docs, a free testing sandbox, and live callbacks, all backed by intelligent routing and low latency. Plus, pay-as-you-go pricing keeps costs predictable as you grow.
REACT INSTANTLY
Our intelligent routing engine and >99.95% platform uptime helps OTPs and alerts arrive fast around the world. SMS is opened by 98% of users, and 90% are read within 3 minutes.
600+ direct carrier paths
Low-latency delivery for critical codes
Scalable infrastructure ready for peak loads
DEVELOPER-CENTRIC EXPERIENCE
Our SMS channel is documented within the unified REST API for the Sinch Conversation Platform. JSON support and clear examples mean less ramp-up time and fewer headaches for your engineering team.
Official SDKs for popular languages
Free testing sandbox to validate flows
Concise code samples and quick starts
ACTIONABLE DELIVERY INSIGHTS
Delivery callbacks post real-time statuses to your webhook for proactive user experiences and rapid issue resolution.
Delivered, failed, and queued events
Data ready for dashboards or logs
Confidence to meet compliance needs
TOP USE CASES
FEATURES AT A GLANCE
The SMS API by Sinch is part of the Conversation API and allows your app to send text messages with a POST request. Sinch routes each message through optimal carriers and posts real-time delivery or failure status to your webhook:
1. API Call: Your application makes a POST request to the Sinch SMS API endpoint with recipient, sender ID, and message body.
2. Intelligent Routing: Sinch selects the best carrier path for speed and reliability.
3. Status Callback: A real-time delivery or failure update is sent to your webhook.
To get started, you’ll need a Sinch account, an API token, a service plan with a virtual number, and a development environment capable of HTTP requests. Create a Sinch account, generate an API token, set up a service plan with a virtual number, and make an HTTP POST to the SMS endpoint. Use the free sandbox to test, then switch to live credentials.
Yes. Use Dynamic Sender ID to choose alphanumeric IDs, short codes, or long numbers for every region. Registering your sender ID helps prevent spoofing and speeds approval.
Yes. The API offers global coverage to 190+ countries through 600+ direct carrier connections.
Sinch posts a real-time delivery or failure status to your configured webhook, giving you full visibility into each SMS.
Rate limits depend on your service plan. Contact support to review limits tailored to your specific traffic needs.
It automatically concatenates messages longer than 160 characters, so the user receives one complete text.
All traffic is secured with HTTPS. The platform is GDPR compliant and ISO 27001 certified. The platform includes tools for managing opt-outs, and our experts actively manage carrier rules and country-specific regulations to simplify global compliance.
Pricing is pay-as-you-go on a per-message basis. Costs vary by destination and routing profile (e.g., transactional vs. promotional).
The platform uses low-latency routing and >99.95% uptime for time-critical codes. SMS engagement is strong, with 98% open rates and 90% read within 3 minutes.