Do "Sign in with Google/Facebook" buttons share more data than a regular signup?
No — by default, both send the site roughly the same three things a regular signup form asks for anyway: your name, your email, and a profile picture. Your password never leaves Google or Facebook either way. The real differences aren't in that first handshake — they're in what happens after, in a documented case where Facebook's login API let far more than identity data leak out, and in tracking that runs on the page whether or not you ever click the button at all.
What data actually gets shared when you click the button
Both Google and Facebook default to the same minimal set: your name, your email address,
and your profile picture. Technically this is the openid, email,
and profile scopes — the standard identity fields, nothing more, unless the
site specifically asks for additional permissions and you approve them on the consent
screen.
Where Google and Facebook actually differ
Facebook's login API has historically supported — and still supports — optional scopes that Google's login has no equivalent for: your public posts, your likes, your events, your friend list. A 2023 academic evaluation of OAuth usage across the web found a distinct cluster of scopes requested only through Facebook Login, with nothing comparable available via Google. That doesn't mean every site requesting Facebook login asks for those extra permissions — most don't — but the option exists on Facebook's side in a way it structurally doesn't on Google's.
Your password never reaches the website, on either provider
This is the actual security improvement social login provides over typing a new password into every site you sign up for. Both buttons use OAuth 2.0: you authenticate directly with Google or Facebook, approve what the site can see, and the provider hands the site a short-lived access token plus an ID token confirming who you are — never your password itself. A site that only offers social login has no password of yours to leak in a breach, because it never had one.
The 2018 Cambridge Analytica case: what Facebook Login actually exposed before 2015
Before Facebook restricted its API, logging in to a single quiz app didn't just share your own profile — it could hand the app data about your friends too, without them ever installing anything themselves. In 2014, a researcher's personality-quiz app used exactly this permission structure to collect data on roughly 270,000 people who took the quiz, and, through their friend networks, information tied to as many as 87 million Facebook profiles eventually reached Cambridge Analytica. Facebook began restricting friend-data access in 2014 and fully deprecated the old API for all remaining apps by April 2015, then tightened app review further in 2018 in direct response to the scandal.
The tracking risk that has nothing to do with clicking the button
Rendering a "Log in with Facebook" button on a page requires loading Facebook's SDK JavaScript on that page — and that SDK can register that a specific Facebook account visited the page, independent of whether that visitor ever clicks the button. The same applies to Google's identity library used to render its button. A regular email/password signup form has no equivalent exposure, because it doesn't need to load a third party's tracking script just to display the form.
This is the part most "social login vs. regular signup" comparisons skip entirely, and it's arguably the bigger everyday difference — it applies to every visitor on every page that button sits on, not just the ones who log in. It's a different mechanism from a supercookie, but the same underlying problem: an identifier that tracks you through a channel a regular signup form simply doesn't open.
Regular email/password signup: what you're actually trading for it
No third party learns you visited the site at all, and no OAuth token exists for anyone to later revoke or abuse. What you're trading for that is direct exposure: the site itself collects your password (hashed, ideally, though not every site does this correctly) and stores your email directly in its own database with nothing standing between you and however that site chooses to use it. Password reuse across sites is the practical risk here — a breach at one site with a reused password exposes every other account using the same credentials, something OAuth login structurally can't do since no password exists to reuse.
So which one actually shares more?
| Factor | Sign in with Google/Facebook | Regular email/password signup |
|---|---|---|
| Password exposure to the site | None — no password ever sent | Site stores your password (hashed, if implemented correctly) |
| Data shared at signup | Name, email, profile picture (default scope) | Whatever the form asks for — often the same three fields |
| Third-party tracking exposure | SDK on the page can log visits even without a click | None, unless the site adds separate tracking scripts |
| Revocable after the fact | Yes — one click in your Google/Facebook account settings | No — you must contact the site or delete the account directly |
| Breach exposure if the site is hacked | No password to steal; access token is short-lived and revocable | Password hash (or worse, plaintext) is exposed with the rest of the database |
Neither option is straightforwardly "more private." Social login trades a small, mostly invisible tracking surface for a meaningfully better breach and password story. Regular signup avoids that tracking surface entirely but leaves you fully dependent on the site's own security practices for a password you've now created yet another copy of.
How to reduce exposure either way
- Prefer Sign in with Apple when it's offered — it hides your real email behind a relay address, so the site never actually sees your inbox.
- Check what a site actually requested, not just that you clicked "Continue with Facebook" — the consent screen lists exact scopes before you approve.
- Audit your linked apps periodically at myaccount.google.com/permissions and facebook.com/settings?tab=applications, and revoke anything you no longer use.
- Use a password manager with unique passwords if you choose regular signup, so a breach at one site can't cascade into others.
- Confirm the button leads to the real domain before entering anything — a fake "Sign in with Google" overlay pointing to a lookalike page is a standard phishing technique, not a genuine OAuth screen.
Does the website get my Google or Facebook password when I use social login?
No. OAuth (the protocol behind both buttons) is built specifically so your password never leaves Google or Facebook. The site receives a short-lived access token and an ID token confirming your identity and the specific fields you approved — never your credentials. This is true regardless of which provider you use.
Can Google or Facebook see what I do on a site after I log in with them?
Not through the login itself. Google states directly that once your account is linked, it doesn't receive access to your activity inside that app, and doesn't use Sign in with Google data for ads or other Google products. The exception is if the site separately embeds a Facebook or Google tracking script — a Like button, a Facebook Pixel, a "Sign in with Google" JS library loaded on every page — which can observe your visit independent of whether you ever click login. That's a tracking-script decision, not a consequence of the login button itself.
Is "Sign in with Apple" more private than Google or Facebook?
For one specific thing, yes: Apple lets you hide your real email behind a random relay address (name@privaterelay.appleid.com) that forwards mail without exposing your actual inbox. Google and Facebook logins always hand over your real registered email. Apple also states it doesn't build an advertising profile from sign-in activity. It doesn't change anything else covered on this page — the password-never-shared and revocable-access mechanics are identical across all three.
How do I revoke a site's access after using social login?
Two dashboards, not the site itself: myaccount.google.com/permissions for anything linked through Google, and facebook.com/settings?tab=applications for Facebook. Removing an app there revokes its access token immediately — but it does not delete data the site already copied into its own database before you revoked it. For that, you still need to contact the site or use its account-deletion tool.
Does having the Facebook Login button on a page track me before I click it?
It can, and this is the part most comparisons of "social login vs. regular signup" leave out entirely. Loading the Facebook SDK to render the button also loads Facebook's tracking cookie logic on that page, which can register that a page was visited by a specific Facebook account — whether or not the visitor ever clicks the button. A site using only an email/password form and no social SDKs doesn't create this exposure at all.
Why do some sites ask for so many Facebook permissions during login?
Because Facebook's login API historically supported (and still supports) optional scopes well beyond identity — things like your public posts, likes, or events — that Google's equivalent login never offered. A 2023 academic study of OAuth usage across the web found a distinct set of scopes requested only through Facebook Login, with no Google equivalent. A site requesting more than your name, email, and profile picture is asking for more than login requires — that's worth noticing and declining if the extra access isn't obviously necessary for the app's function.