Passwordless Authentication: Magic Links vs Passkeys vs OTP

Logging in should be easy.

But for years, most systems have depended on passwords—things people forget, reuse, or save in unsafe ways. That’s not just annoying; it’s risky. Stolen passwords are still one of the main reasons accounts get hacked.

Passwordless authentication changes this. Instead of asking users to remember something, it checks something they already have, like their phone, email, or device. This makes logins quicker and safer.

The three most common methods today are Magic Links, Passkeys, and One-Time Passwords (OTP), and each works a little differently, so it’s important to know which one suits your system best.

Why Organizations Are Moving Away From Passwords

Passwords were designed for a very different internet. Today’s systems are distributed, cloud-based, and accessed from multiple devices and locations. In this environment, passwords create more problems than they solve.

Users forget them, reuse them, or fall for phishing attempts. Security teams must defend against credential stuffing and database leaks. Support teams handle constant reset requests. Even strict password rules don’t eliminate these issues; they usually just increase friction.

Passwordless authentication removes the stored secret entirely. If there’s no password database, there’s nothing to steal. This shift reduces breach impact, simplifies login, and lowers operational overhead. For many organizations, passwordless adoption is both a security decision and a product decision.

How Passwordless Authentication Works

All passwordless systems rely on verification rather than memorization. Instead of comparing a typed password to a stored value, the system checks whether the user can prove control of a trusted factor. That factor might be a device, email account, phone number, or cryptographic credential.

When someone logs in, the server generates a temporary challenge or token. The user completes a step that proves they control the trusted factor. If the proof is valid, access is granted.

Because nothing reusable is shared, attackers cannot simply steal credentials and log in later. Each authentication attempt requires fresh verification.

The Main Types of Passwordless Authentication

Passwordless authentication isn’t one technology. It’s a category of methods, each with different strengths and trade-offs.

The three most widely used approaches today are magic links, passkeys, and OTPs. Understanding how each works helps teams design authentication systems that balance usability, security, and technical effort.

Magic Links

Magic links authenticate users through a one-time login URL sent to their email. Instead of entering credentials, the user clicks the link and is signed in. The system assumes that whoever controls the inbox is the legitimate account owner.

This method is popular because it removes almost all friction. Users don’t need to remember anything or type anything. For onboarding flows, that simplicity can significantly improve conversion rates.

How they work

The user enters an email address. The server generates a unique login link containing a short-lived token and sends it to the inbox. When clicked, the server verifies the token and logs the user in.

Best use cases

Magic links work well for low-risk environments such as:

• SaaS platforms
• Community tools
• Trial accounts
• Content portals

Limitations

Security depends entirely on email security. If an attacker gains access to the inbox, they can log in. Phishing emails can also trick users into clicking malicious links. For this reason, magic links are best used where convenience is more important than maximum security, or when combined with additional verification.

Passkeys

Passkeys are a newer authentication method built on public-key cryptography. When users register, their device creates a key pair. The public key is stored on the server, while the private key stays securely on the device.

During login, the server sends a challenge that the device signs with the private key. Because the private key never leaves the device, it cannot be stolen from a server breach or intercepted during transmission. Many systems also require biometric or device unlock confirmation, ensuring the person holding the device is the owner.

Passkeys are widely considered the strongest mainstream authentication method available today.

Best use cases

They’re ideal for environments that require strong protection, including:

• Financial platforms
• Enterprise dashboards
• Administrative systems
• Developer infrastructure

Limitations

Passkeys require modern device and browser support, and recovery flows must be carefully designed. If a user loses access to their device, there must be a secure way to regain access without weakening protection.

One-Time Passwords (OTP)

One-time passwords verify identity using temporary codes delivered through SMS, email, or authenticator apps. Each code is valid only once and usually expires within minutes.

OTPs remain widely used because they’re familiar. Most users already understand how to enter a verification code, which makes adoption easy even for non-technical audiences.

How they work

The user enters an identifier such as phone number or email. The system sends a short-lived code. The user enters it, and the server validates it.

Best use cases

OTPs are commonly used for:

• Multi-factor authentication
• Backup login methods
• Systems needing quick deployment
• Broad consumer audiences

Limitations

SMS-based OTP can be intercepted or redirected through SIM-swap attacks. Codes can also be phished if users enter them on fraudulent sites. Authenticator app codes are generally safer because they’re generated locally.

Comparing the Three Approaches

Each method prioritizes different goals. Some maximize convenience, others security, and others ease of implementation. Comparing them side by side helps clarify where each fits best.

The key takeaway is that no single method is universally best. The right choice depends on context.

Choosing the Right Method for Your System

Authentication should reflect real-world risk, not assumptions. A discussion forum doesn’t need bank-level authentication, while a financial dashboard shouldn’t rely on lightweight login methods. The best approach is to match authentication strength to the sensitivity of what’s being protected.

Selecting the right method requires evaluating technical, user, and security factors together.

Risk Sensitivity

The higher the value or sensitivity of an account, the stronger the authentication should be. Administrative tools, payment platforms, and data systems should lean toward passkeys or cryptographic login. Low-risk platforms like newsletters or trial apps can prioritize convenience with magic links.

User Environment

Consider the devices and connectivity your users rely on. If many use older phones or shared computers, passkeys may not be practical as the only method. If users frequently change devices, recovery flows become especially important.

Threat Model

Different platforms face different threats. Consumer apps often face credential stuffing and phishing. Enterprise systems may face targeted attacks. Understanding likely attack scenarios helps determine whether you need phishing-resistant authentication or simply frictionless login. For more on securing the tokens issued after login, see our guide on JWT security best practices.

Adoption Friction

Strong authentication is only effective if users adopt it. If a method feels confusing or inconvenient, users may avoid it or abandon signup altogether. Choose an approach your audience can realistically use.

Recovery and Support Requirements

Account recovery is one of the most overlooked parts of authentication design. If users lose access to their factor, they must be able to recover safely. Weak recovery flows can undermine even the strongest login system.

When these factors are considered together, authentication becomes a deliberate architectural choice rather than a default configuration.

Hybrid Passwordless Strategies

Many mature systems combine multiple passwordless methods instead of relying on just one. This layered approach improves resilience and prevents lockouts if a single factor becomes unavailable.

For example, a platform might use passkeys as the primary login method but allow OTP as backup. Another system might start with magic links and later prompt users to enroll a passkey. These combinations provide flexibility without sacrificing security.

Hybrid strategies also support gradual rollout. Teams can introduce stronger authentication over time instead of forcing users to switch immediately. If your system also uses OAuth 2.0 for delegated access, see our guide on OAuth 2.0 security best practices to keep token flows secure alongside passwordless login.

Implementation Considerations Teams Often Miss

Choosing a method is only the beginning. The real security of a passwordless system depends on how it’s implemented. Even strong authentication methods can become vulnerable if operational safeguards are missing.

Teams should plan for:

• Short expiration windows
• Replay-attack prevention
• Rate limiting
• Monitoring unusual login behavior
• Secure recovery flows
• Logging and audit trails

Authentication isn’t just a login feature. It’s an ongoing system that requires monitoring, maintenance, and periodic review.

Business and User Experience Benefits

Passwordless authentication isn’t only a security improvement. It often produces measurable business and usability gains as well.

Removing passwords simplifies onboarding, reduces friction, and lowers support costs. These advantages make passwordless adoption attractive not just to security teams, but to product and operations teams too.

Faster Onboarding and Higher Conversion

Long signup flows cause drop-offs. Passwordless login removes one of the biggest barriers—creating and remembering credentials. When users can sign in instantly through a link or device confirmation, they’re more likely to complete registration and return later.

Reduced Support and Operational Costs

Password resets are one of the most common support requests. Eliminating passwords dramatically reduces these tickets. That saves time for support teams and lowers operational expenses for organizations at scale.

Stronger Security Without Added Friction

Traditional security often increases friction. Passwordless flips that dynamic. Many methods, especially passkeys, provide stronger protection while making login faster. This rare combination of better security and better experience is a major reason organizations are adopting passwordless systems.

When Passwordless May Not Be Ideal

Despite its advantages, passwordless authentication isn’t always the best choice. Some systems still rely on traditional credentials due to infrastructure, regulatory, or environmental constraints.

Legacy systems may not support modern authentication protocols. Offline environments may require local credentials. Certain compliance frameworks mandate specific authentication factors. In these cases, organizations often adopt passwordless gradually or use hybrid approaches instead of replacing passwords entirely.

The goal isn’t to eliminate passwords everywhere. It’s to choose the authentication method that best fits your system’s realities.

Bottom Line

Passwordless authentication is changing how modern applications handle login and identity verification. Magic links, passkeys, and OTPs each have their own strengths, and no single method is right for every scenario. The best choice depends on your users, your risk level, and how sensitive your platform or data is.

What really makes the difference is thoughtful implementation. When authentication is built with strong safeguards, monitoring, and reliable recovery options, passwordless systems can deliver solid security while keeping access fast and easy—without the usual challenges that come with passwords.

To make this easier to implement, Authgear offers tools and infrastructure that help teams deploy secure, scalable passwordless authentication with confidence.

Get started with Authgear today to streamline passwordless adoption, follow security best practices, and scale your authentication systems safely from day one.

FAQs

What is the most secure passwordless authentication method?

Passkeys are generally considered the strongest because they rely on cryptographic keys that never leave the user’s device, making them resistant to phishing and credential theft.

Are magic links secure enough for production systems?

Yes, if implemented correctly with short expiration times, single-use tokens, and HTTPS delivery. They’re best suited for low- to moderate-risk environments.

Is OTP considered passwordless authentication?

Yes. OTP can function as a standalone passwordless method or as an additional factor alongside another login mechanism.

Which OTP type is safest?

Authenticator app codes are typically safer than SMS because they don’t depend on telecom networks and can’t be intercepted through SIM-swapping.

Should companies remove passwords completely?

Not necessarily. Many organizations adopt hybrid approaches where passwordless methods are primary and passwords remain only as backup or for legacy compatibility.