react-native-confirmation-code-field is a small, well-designed React Native component for one-time-code entry, and the security of an OTP flow that uses it depends far more on the surrounding logic, rate limiting, expiry, and verification, than on the input component itself. The library gives you an accessible, customizable code field in roughly 3.8 KB, which is exactly the right scope for a UI primitive. This guide covers what react-native-confirmation-code-field does, how to wire it up cleanly, and, more importantly, how to build the one-time-password flow around it so the nice UI is not sitting on top of a weak verification path.
What the Library Does
react-native-confirmation-code-field renders a row of cells for entering a confirmation or verification code, the kind of screen you see after requesting a one-time password over SMS or email. Its design is deliberately low-level: it gives you a stretchable, invisible TextInput layered over cell components, and lets you render each cell however you want, so the visual style is entirely yours.
It ships the pieces you actually need. The main CodeField component drives input; Cursor renders a blinking caret; and two hooks, useBlurOnFulfill and useClearByFocusCell, handle blurring when the code is complete and clearing a cell on focus. It supports iOS and Web fast-paste of SMS codes and custom paste handling on Android, exposes a TextInput ref, and is compatible with the React Compiler. A minimal setup looks like this:
import {
CodeField,
Cursor,
useBlurOnFulfill,
useClearByFocusCell,
} from 'react-native-confirmation-code-field';
const CELL_COUNT = 6;
function OtpInput({ value, setValue }) {
const ref = useBlurOnFulfill({ value, cellCount: CELL_COUNT });
const [props, getCellOnLayoutHandler] = useClearByFocusCell({ value, setValue });
return (
<CodeField
ref={ref}
value={value}
onChangeText={setValue}
cellCount={CELL_COUNT}
keyboardType="number-pad"
textContentType="oneTimeCode"
autoComplete="sms-otp"
renderCell={({ index, symbol, isFocused }) => (
<Text key={index} onLayout={getCellOnLayoutHandler(index)}>
{symbol || (isFocused ? <Cursor /> : null)}
</Text>
)}
{...props}
/>
);
}
Setting textContentType="oneTimeCode" on iOS and autoComplete="sms-otp" on Android is what enables the OS to auto-fill a code from a received SMS. That is a usability win, and it does not weaken security, because the OS keeps the user in control of the autofill.
The Library Is Not Your Security Boundary
This is the point that matters most. A code-entry component is a presentation layer. It collects six digits and hands them to your code. It cannot, and should not be expected to, enforce anything about whether those digits are correct, fresh, or being brute-forced. Every meaningful control lives on the server and in your flow logic. Treat the field as untrusted input just like any other text box, and put the security where it belongs.
Securing the OTP Flow
Generate codes properly. Use a cryptographically secure random generator on the server, never Math.random. A six-digit numeric code has only a million possibilities, which is fine only because the other controls below make guessing impractical.
Expire codes quickly. A one-time code should live for a short window, commonly a few minutes, and become invalid the moment it is used or a new one is issued. A code that stays valid for an hour is a code an attacker has an hour to guess or intercept.
Rate limit and lock out. This is the single most important control. With only a million combinations, a six-digit code is trivially brute-forceable without server-side limits. Cap verification attempts per code and per account, add exponential backoff, and invalidate the code after a small number of failures so the user must request a fresh one. Rate-limit code issuance too, so an attacker cannot spam a victim with texts or exhaust your SMS budget.
Verify server-side, always. Never compare the entered code against a value the client can see. Compare on the server using a constant-time comparison so response timing does not leak how many digits matched.
Bind the code to context. Tie each code to the specific user, session, and purpose (login versus password reset versus transaction confirmation) so a code issued for one action cannot be replayed for another.
Mind the transport. SMS OTP is phishable and vulnerable to SIM-swap; it is better than nothing but weaker than an authenticator app (TOTP) or a passkey. If your threat model warrants it, offer or prefer app-based codes. Whatever the channel, never log the code, and make sure it is not captured in analytics or crash reports.
Keep the input UX safe. Use keyboardType="number-pad" for numeric codes, disable autocorrect, and lean on the OS one-time-code autofill hints shown above. Good autofill reduces the temptation for users to reuse or write down codes, which is a real, if soft, security benefit.
Keeping the Dependency Healthy
react-native-confirmation-code-field is small and focused, which is a good sign, but it is still a third-party dependency in your mobile app, and mobile apps have their own supply chain. Pin the version, commit your lockfile, and keep it in your dependency scanning so a future advisory against it or its transitive dependencies surfaces promptly. An SCA tool such as Safeguard tracks mobile JavaScript dependencies the same way it tracks server-side ones, so a flagged package in your React Native bundle does not slip through just because it runs on a device rather than a server.
Bottom Line
react-native-confirmation-code-field is a good choice for OTP entry: small, accessible, customizable, and mindful of the platform autofill affordances. Use it for the UI, and put your real effort into the flow around it, secure generation, short expiry, strict rate limiting, server-side constant-time verification, and context binding. The prettiest code field in the world does not help if an attacker can try a million guesses; get the flow right and this library gives you the clean front end to match.
FAQ
Does react-native-confirmation-code-field make my OTP flow secure?
No. It is a UI component for entering a code. Security comes from your server-side flow: secure code generation, short expiry, strict rate limiting, and constant-time verification. Treat the field's output as untrusted input.
How do I enable SMS code autofill with this library?
Set textContentType="oneTimeCode" for iOS and autoComplete="sms-otp" for Android on the CodeField. The OS then offers to fill the code from a received SMS, which improves usability without weakening security.
What is the most important control for a six-digit OTP?
Rate limiting and lockout. With only a million combinations, a six-digit code is easy to brute-force without server-side attempt limits. Cap attempts per code and account, add backoff, and invalidate the code after a few failures.
Is SMS OTP secure enough?
It is better than no second factor but weaker than app-based TOTP or passkeys, because SMS is phishable and exposed to SIM-swap attacks. If your threat model is elevated, prefer or offer authenticator-app codes, and never log the OTP anywhere.