SMS Auth

SMS, finally reliable.

Five-plus providers, weighted live by delivery and latency per carrier. Every request lands on the route that's working right now — no single point of failure.

Talk to our team See the routing
SMS Auth · live routingAuto
→ request+91 98765 43210
Provider 199%
Provider 297%
Provider 394%
Provider 468%
Provider 591%
Provider 688%
picked per carrier · per hour2.4s median
5+
Providers, per carrier
99.4%
Median delivery rate
200+
Markets, global
2.4s
Median time to deliver
Why ours

A single provider is a single point of failure.

When a carrier throttles or a provider has a peak-hour outage, OTPless reroutes the same request to a healthier route — mid-flight, before a single login fails.

A single-provider stack means one outage on a high-traffic day breaks every login, and per-carrier delivery swings 30%+ — you pay for failed sends.

OTPless weights multiple providers live, carrier by carrier. A degraded route triggers an automatic shift within the same request — no failed sends, no support ticket.

SMS Auth · failover+2.4s
T+0ms›Route request · carrier Jio
T+40ms!Provider 4 delivery −22% this hour
T+60ms×Provider 4 health check failed
T+90ms›Re-weighting pool · 5 healthy routes
T+2.4s✓Delivered via Provider 1 · verified
rerouted in-flight · 0 failed sends99.4% delivered
Bank-grade delivery

Your OTP gets its own pipeline.

One-time passcodes ride a dedicated, bank-grade lane with the provider — isolated from promotional and transactional traffic.

No congestion, no peak-hour queue, no marketing blast in front of your login. The path that carries your OTP does one job, so it stays fast when everything else is busy.

SMS provider · delivery lanes
Promotionalshared queue · delayed
Transactionalshared queue · variable
OTP · dedicatedpriority · 2.4s
Your OTP never waits behind a marketing blast.
How SMS Auth works

One call. Multiple providers behind it.

You hand us a phone number. We pick the route that's working right now, send the OTP, and verify it back.

01 · Route per carrier
Multiple providers, picked in real time.
We watch delivery rate, latency, and operator health per circle, per provider, per hour. Each request lands on the route most likely to deliver in under three seconds.
02 · Branded sender ID
The user sees ACME, not a shortcode.
Where regulations allow, your sender ID appears on the SMS. Where they don't, we fallback to common sender ID. Either way, the OTP looks like it came from you.
03 · Auto-read on Android
The SDK reads the OTP. No typing.
Using the SMS Retriever API, the OTPless SDK picks the code straight out of the inbox the moment it arrives — bound to your app's signing hash. No SMS-read permission required.
Integration

One call. Every provider routed for you.

You pass a phone number and your app's signing hash. OTPless routes across providers, sends the OTP, auto-reads it on Android, and returns a signed token.

SignInActivity.kt android · kotlin 
import com.otpless.main.OtplessManager
import com.otpless.dto.HeadlessRequest
import com.otpless.dto.HeadlessResponse

// 1. Init the OTPLESS view in your sign-in activity
private val otplessView = OtplessManager
    .getInstance().getOtplessView(this)

// 2. Verify over SMS — phone + your app hash
val request = HeadlessRequest()
request.setPhoneNumber("91", "9876543210")
request.setChannel("SMS")            // routed across providers

// 3. Start headless auth — auto-read via SMS Retriever
otplessView.startHeadless(request, ::onHeadlessCallback)

private fun onHeadlessCallback(res: HeadlessResponse) {
    if (res.statusCode == 200 &&
        res.responseType == "ONETAP") {
        val token = res.response.optString("token")
        // → verify token on your backend
    }
}
// build.gradle  implementation 'io.github.otpless-tech:otpless-android-sdk:2.5.3'
onHeadlessCallback · ONETAP
2.4s
auths[0] · primary
channelSMS
statusSUCCESS
autoReadtrue
verifiedAt1778612141195
routing
providerp1
pipelineotp · dedicated
senderIdACME
latency2.4s
device: iQOO I2410 · Android 16 region: in
Customer Outcomes

The numbers our customers ship with.

* Metrics measured against pre-OTPless baselines.

25M+
Logins / month
"OTPless completely transformed how users log in at Meesho — fast, effortless, and frustration-free. Over 25 million seamless logins every month and a 10% boost in conversion."
AV
Arjit Verma
Associate Director · Meesho
98%+
Login success
"Astrotalk partnered with OTPless to simplify login, reduce operational complexity, and support international scale. Zero-touch flows and intelligent routing delivered measurable impact on conversion, cost, and experience."
Siddharth Singh · CTO · Astrotalk
Lower
SMS spend
Mudit Yadav
PM · Pickrr (Shiprocket)
94.1%
Login success
Ankit Bhatia
Product Head · Seekho
Frequently asked

Common questions.

What is OTPless SMS Auth?
SMS Auth delivers your login OTP over SMS, but routed intelligently across 5+ providers per carrier and verified for you. It's the universal channel — works on every phone, every network, no app required — made reliable through live routing and a dedicated OTP pipeline.
How does multi-provider routing work?
OTPless tracks delivery rate, latency, and operator health per carrier circle, per provider, per hour. Each request is sent on the route most likely to deliver fastest. If a provider degrades mid-request, traffic shifts to a healthier route automatically — no failed sends.
What is a dedicated OTP pipeline?
Your one-time passcodes travel on a bank-grade lane that is isolated from promotional and transactional SMS. Because that path does one job, your OTP never queues behind a marketing blast or a peak-hour transactional surge — so it stays fast when volume spikes.
Does the OTP auto-read? On which platforms?
On Android, the SDK reads the code directly via the SMS Retriever API — bound to your app's signing hash, with no SMS-read permission required. On iOS, the code surfaces as a one-tap autofill suggestion on the keyboard.
Can the SMS show our brand?
Yes. Where regulations allow, your branded sender ID appears on the message. Where they require it, OTPless uses your approved DLT template. Sender ID, DLT, and per-region compliance are all managed in OTPless — you ship one SDK call.
How reliable and fast is it?
99.4% median delivery across 200+ markets, with a ~2.4s median time to deliver. Multi-provider failover and the dedicated OTP pipeline keep those numbers steady through carrier outages and peak-hour congestion.
Start with SMS Auth

SMS that just delivers.

Multiple providers behind one SDK call, a dedicated OTP pipeline, branded sender IDs, and Android auto-read. We'll benchmark your current SMS funnel against an OTPless cohort within a week.

Talk to our team Read the docs
SOC 2 · ISO 27001 · 500M+ logins / quarter