Guides for everyone who sends messages
Country-by-country SMS rules and prices, phone number formats, area codes, and step-by-step code for every major messaging provider.
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- 1,498
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Code examples
Step-by-step Node.js tutorials for sending SMS, MMS and WhatsApp with Twilio, Vonage, Sinch, Plivo, Infobip, MessageBird and AWS SNS.
472 articles
Area codes
North American area codes: where each one is, the cities it covers, and how to dial it.
295 articles
SMS compliance
Country-by-country rules for sending SMS: sender IDs, consent and opt-out, content restrictions, and US 10DLC registration.
245 articles
Phone number standards
How phone numbers are written in each country: formats, area codes, E.164 and validation.
225 articles
SMS pricing
What an SMS costs in each country, which providers carry it, and how to keep the bill down.
223 articles
Messaging channels
Building on WhatsApp, RCS, MMS and two-way messaging, from first message to delivery receipts.
25 articles
Tools
Reference guides for number formatting and numbering rules, plus a few integration walkthroughs.
12 articles
Legal
Sent's commercial license order form. The Terms of Service and every other policy are on the Legal page.
1 article
Recently updated
All categories- Area codesArea Code 201 New Jersey: Complete Guide to Coverage, Cities & Phone Numbers (2025)Area code 201 serves northeastern New Jersey including Jersey City, Hoboken, and 13+ major cities. Learn about 201 phone numbers, coverage map, history, and telecom providers in this complete 2025 guide.
- ToolsFCC Direct Numbering Authorization for Interconnected VoIP ProvidersComplete guide to obtaining FCC authorization for VoIP providers to secure telephone numbers directly from numbering administrators without carrier intermediaries.
- Code examplesBuild an Appointment Scheduler with SMS Reminders Using RedwoodJS and VonageLearn how to build a full-stack appointment scheduling application with automated SMS reminders using RedwoodJS v8.x and Vonage SMS API v3.24.1. Complete tutorial with code examples.
- Code examplesBuild SMS Marketing Campaigns with Node.js, Express & Vonage Messages API (2025 Guide)Complete tutorial for building SMS marketing campaigns using Node.js, Express.js, and Vonage Messages API. Includes two-way messaging, webhook integration, TCPA compliance, JWT security, and marketing campaign best practices.
- Code examplesBuild SMS Scheduling and Reminders with Vite, React, Node.js, and Vonage Messages APIComplete step-by-step guide to building an SMS scheduling application with Vite, React, Node.js, Express, and Vonage Messages API. Learn to schedule SMS reminders, handle webhooks, manage timezones, and deploy production-ready solutions with BullMQ or Agenda.
- Messaging channelsBuilding a Production-Ready Node.js Application with Vonage SMS and WhatsApp Integration Using ExpressComplete guide to building Node.js Express applications for Vonage Messages API. Learn SMS/WhatsApp integration, webhook handling, security best practices, Prisma ORM setup, and production deployment strategies.
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