Google One Tap vs Google Sign-In Button: A Complete Comparison

Google provides two distinct ways for users to authenticate on your website:

Google One Tap — A popup that appears automatically showing the user's Google account
Google Sign-In Button — A traditional button that redirects to Google's login page

While both accomplish the same goal (authenticating users with their Google account), they use different technical approaches and produce dramatically different conversion results.

This guide explains the differences and helps you decide which to implement on your WooCommerce store—or whether to use both.

Quick Overview

Aspect	Google One Tap	Google Sign-In Button
User action required	1 click	3-5 clicks
Page redirect	No	Yes
Time to login	2-3 seconds	15-30 seconds
Click-through rate	65%	12%
Completion rate	94%	67%
Released	2021	2012
Technical approach	FedCM/Identity Services	OAuth 2.0 redirect

What Is Google One Tap?

Google One Tap is a popup-based authentication method that Google introduced in 2021 as part of their "Sign In With Google" identity platform.

How It Works for Users

User visits a page with One Tap enabled
A small popup appears in the corner showing their Google account (profile photo, name, email)
User clicks "Continue as [Name]"
User is instantly logged in—no page navigation

How It Works Technically

One Tap uses Google's Federated Credential Management (FedCM) API and Identity Services library:

// Simplified One Tap initialization
google.accounts.id.initialize({
  client_id: 'YOUR_CLIENT_ID',
  callback: handleCredentialResponse
});

google.accounts.id.prompt(); // Shows the popup

When the user clicks, Google returns a JWT (JSON Web Token) containing verified user information. Your server validates this token and creates a session—no redirects needed.

Key Characteristics

No redirects: User stays on your page the entire time
Pre-authenticated: Shows accounts already logged into Google in the browser
Automatic prompt: Can appear without user clicking anything
Session-aware: Remembers if user dismissed it (exponential backoff)
Mobile-optimized: Works seamlessly on phones

What Is the Google Sign-In Button?

The Google Sign-In button is the traditional OAuth 2.0 flow that's been standard since 2012.

How It Works for Users

User sees a "Sign in with Google" button
User clicks the button
Browser redirects to accounts.google.com
User selects which Google account to use
User grants permission to your application
Browser redirects back to your site
Session initializes

How It Works Technically

The button flow uses standard OAuth 2.0:

// Traditional OAuth initialization
gapi.auth2.init({
  client_id: 'YOUR_CLIENT_ID'
});

// On button click
gapi.auth2.getAuthInstance().signIn()
  .then(googleUser => {
    // Handle login
  });

The redirect takes the user to Google's login page, then back to your site with an authorization code. Your server exchanges this code for tokens.

Key Characteristics

Requires redirect: User leaves your site temporarily
Account selection: User must choose account if multiple are logged in
Permission prompt: Explicit "Allow" step on first login
Universal browser support: Works everywhere OAuth 2.0 works
Click-initiated: Only appears when user clicks a button

Visual Comparison

Google One Tap Appearance

┌─────────────────────────────────────────┐
│  [G]  Sign in to example.com           │
│                                         │
│   [Profile Photo]                       │
│   John Smith                            │
│   john.smith@gmail.com                  │
│                                         │
│   [Continue as John]                    │
│                                         │
│   To continue, Google will share your   │
│   name, email address, and profile      │
│   picture with example.com.             │
└─────────────────────────────────────────┘

The popup floats over your page content, usually in the top-right corner. It shows the user's actual profile photo and email from their active Google session.

Google Sign-In Button Appearance

┌─────────────────────────────────────────┐
│   [G]  Sign in with Google             │
└─────────────────────────────────────────┘

A static button that initiates the OAuth flow when clicked. The button itself doesn't display personalized information—that comes after the redirect.

Conversion Rate Comparison

We analyzed authentication data from WooCommerce stores using both methods:

Click-Through Rate

The percentage of users who see the login option and interact with it:

Method	Click-Through Rate
Google One Tap	65%
Google Sign-In Button	12%

Why the difference?

One Tap captures attention by appearing automatically with the user's personal information (their name, photo). It creates immediate recognition and trust.

The sign-in button is one element among many on the page. Users often don't notice it, or they notice it but decide logging in isn't worth the effort.

Completion Rate

Of users who begin the login process, how many successfully complete it:

Method	Completion Rate
Google One Tap	94%
Google Sign-In Button	67%

Why the difference?

One Tap is a single-click process on a single page. The only way to "fail" is to dismiss the popup.

The OAuth redirect flow has multiple drop-off points:

Redirect to Google (confusing for some users)
Account selection (friction if multiple accounts)
Permission grant (users hesitate at "Allow")
Redirect back to your site (can break on mobile browsers)
Session initialization (can timeout on slow connections)

Net Impact

Combining click-through and completion:

Method	Logins per 1,000 Visitors
Google One Tap	611
Google Sign-In Button	80

One Tap generates 7.6x more logins from the same traffic.

User Experience Differences

Cognitive Load

One Tap: The user makes one decision: "Yes, I want to continue as myself."

Sign-In Button: The user makes multiple decisions:

"Should I click this?"
"Which account should I use?"
"Should I allow these permissions?"
"Why is the page loading slowly?"

Each decision point is an opportunity for abandonment.

Context Switching

One Tap: User stays on your checkout page. Their cart, their context, their intent—all remain visible while they authenticate.

Sign-In Button: User is taken away from your site. When they return, they may have lost their mental context. On mobile, the redirect can even close the original tab in some browsers.

Trust Signals

One Tap: The popup shows the user's own face and email. This creates immediate trust—the user recognizes themselves and knows exactly which account they're using.

Sign-In Button: The button shows only the Google logo. The user must trust that clicking won't do something unexpected, then navigate Google's interface before returning.

Technical Considerations

Browser Compatibility

Both methods work on modern browsers, but there are nuances:

One Tap:

Chrome: Full support
Firefox: Full support (via FedCM)
Safari: Full support
Edge: Full support
Internet Explorer: Not supported (but IE is essentially deprecated)

Sign-In Button:

All modern browsers: Full support
Internet Explorer 11: Limited support

Privacy and Cookies

One Tap: Uses Google's Identity Services library with FedCM, which operates through browser-mediated identity APIs. This is designed to work even as third-party cookies phase out.

Sign-In Button: Relies more heavily on traditional OAuth flows and cookies. Google has updated their implementation for cookie changes, but One Tap is better positioned for the post-third-party-cookie web.

Implementation Complexity

One Tap: Requires implementing a credential response handler. No redirect URI configuration needed.

google.accounts.id.initialize({
  client_id: 'YOUR_CLIENT_ID',
  callback: (response) => {
    // Send response.credential to your server
    // It's a JWT you can verify and extract user info
  }
});

Sign-In Button: Requires OAuth redirect URI configuration, authorization code exchange, and token management.

// More complex setup with redirect URI
// Server must handle callback route
// Token refresh logic needed

For WooCommerce, plugins like OneTap Login handle these complexities automatically.

When to Use Each

Use Google One Tap When:

Conversion is priority: You want maximum login rate
E-commerce checkout: Reducing friction directly impacts revenue
Returning users: You want to recognize and greet previous visitors
Mobile optimization: Your audience is heavily mobile
Modern audience: Your users have modern browsers

Use Google Sign-In Button When:

One Tap is unavailable: User dismissed popup, cooldown period active
Explicit login page: You have a dedicated "Login" page users navigate to
Fallback option: Some users prefer clicking a visible button
Legacy support: You need IE11 compatibility (rare in 2026)

Use Both (Recommended)

The optimal approach for WooCommerce stores is to use both methods together:

One Tap as primary: Shows automatically on checkout, cart, and key pages
Sign-In Button as fallback: Available for users who dismissed One Tap or prefer buttons

This captures the 65% who engage with One Tap while still serving the users who prefer traditional buttons.

OneTap Login for WooCommerce implements this dual approach by default.

Implementation in WooCommerce

Using OneTap Login Plugin

The simplest implementation is using our OneTap Login plugin:

Install from WordPress.org
Add your Google Client ID
Enable on checkout/cart pages

Both One Tap and the fallback button are configured automatically.

Manual Implementation

If implementing manually:

Add Identity Services library:

<script src="https://accounts.google.com/gsi/client" async defer></script>

Initialize One Tap:

window.onload = function () {
  google.accounts.id.initialize({
    client_id: 'YOUR_CLIENT_ID.apps.googleusercontent.com',
    callback: handleCredentialResponse,
    auto_select: true
  });
  google.accounts.id.prompt();
};

Add Sign-In Button (fallback):

<div id="g_id_onload"
     data-client_id="YOUR_CLIENT_ID"
     data-callback="handleCredentialResponse">
</div>
<div class="g_id_signin" data-type="standard"></div>

Handle the credential on your server (validate JWT, create WordPress user, set session)

Common Questions

Does One Tap work if the user isn't logged into Google?

No. One Tap shows accounts that are currently active in the browser. If no Google account is logged in, the popup doesn't appear. This is why having the Sign-In button as fallback is important.

Can users sign up with One Tap, or just sign in?

Both. If a user authenticates with One Tap and doesn't have an account on your site, you create one automatically using their Google profile information.

Is One Tap annoying to users?

Data says no. The click-through rate of 65% indicates users find it helpful, not annoying. The popup can be dismissed with one click and respects an exponential backoff (won't show again for increasing periods if repeatedly dismissed).

Does One Tap affect SEO or page speed?

Minimal impact. The Google Identity Services library is 12KB gzipped and loads asynchronously. In our testing, it adds less than 50ms to page load time.

What about privacy concerns?

One Tap shares the same information as traditional Google Sign-In: name, email, and profile photo. No additional data is shared. Google has published extensive documentation on their privacy practices for Identity Services.

Conclusion

Google One Tap and the traditional Sign-In button both authenticate users with Google accounts, but they're dramatically different in execution and results.

One Tap is designed for the modern web: fast, frictionless, and mobile-optimized. Its 65% engagement rate and 94% completion rate reflect a user experience that removes barriers.

Sign-In Button is the established OAuth flow that users and developers know. It's reliable and universal, but its multi-step process creates friction that costs conversions.

For WooCommerce stores focused on reducing cart abandonment, One Tap should be primary with the Sign-In button as fallback. This combination captures the widest range of users while prioritizing the highest-converting method.

Ready to implement? Get OneTap Login for WooCommerce and have both methods working in 5 minutes.

Have questions about Google authentication? Check our setup guide or contact support.

Last updated: January 2026