The Pricing Table
All prices are for US domestic SMS verification as of March 2026.
| Provider | Per Verification (US) | Free Tier | Failed Attempts | Rate Limiting |
|---|---|---|---|---|
| Auth1 | $0.01 | 1,000/mo | Not charged | Included (Rust) |
| Twilio Verify | $0.05 | None | Charged | Separate add-on |
| Plivo Verify | $0.05 | None | Charged | Not included |
| Vonage Verify | $0.053 | Some free | Not charged if <30s | Not included |
| MessageBird | $0.035 | 10 free | Charged | Not included |
Hidden Costs Nobody Tells You About
Twilio charges per attempt, not per success. If a user enters the wrong code three times before getting it right, that is four attempts at $0.05 each: $0.20 for one verified user. With a 15-20% failure rate, effective cost per successful verification is $0.06-0.07.
Carrier surcharges: ~$0.003/msg for A2P messaging, passed through by every provider. Registration fees: Brand registration ($4 one-time), campaign registration ($15 + $10/month). Phone number costs: Toll-free $2-3/month, short code $1,000-1,500/month.
What You Get Beyond SMS
Auth1: Complete auth platform — JWT management, session management, rate limiting, Argon2id hashing, PII encryption, audit logging, multi-tenant isolation, input sanitization, CSP headers. All in a single 3.1 MB native Rust addon. No additional services, API calls, or billing.
Twilio Verify: OTP generation, SMS delivery, code verification, fraud detection. You still need to build JWT management, session handling, password hashing, and everything else.
The Total Cost of Authentication
If you use Twilio for SMS and build everything else, you are looking at 220-460 engineering hours of auth infrastructure work, plus Twilio's per-verification cost, plus ongoing maintenance. With Auth1, engineering time is measured in hours, not weeks.
Cost Model: 100K Monthly Active Users
300,000 verifications/month with 15% failure rate:
| Provider | Monthly Cost | Annual Cost |
|---|---|---|
| Auth1 | $2,550 | $30,600 |
| Twilio Verify | $17,625 | $211,500 |
| Vonage Verify | $14,734 | $176,813 |
| MessageBird | $12,338 | $148,050 |
The difference between Auth1 and Twilio is $15,000 per month — a senior engineer's salary. And this comparison only covers SMS verification, not the engineering time to build JWT management, session handling, and the dozen other auth features Auth1 includes.
If you need only phone verification, pick the cheapest provider with good deliverability. If you need authentication — not just verification — evaluate the total cost. Auth1 bundles everything into a single library with per-verification pricing for SMS.
When Each Provider Makes Sense
Use Twilio Verify if you already use Twilio for voice/video, need multi-channel verification, and have a team to build the rest of your auth stack.
Use Auth1 if you need complete authentication, want middleware at 4.36us/request, care about PQ security, and want to stop building auth infrastructure from scratch.