Your sign-up method is a conversion decision disguised as a technical one. It sits at the exact point where motivated visitors become users, and the difference between a good choice and a lazy one shows up in your activation rate immediately. Here’s what each option actually costs you.
The options, honestly assessed
Email and password
For: universal, no third-party dependency, works for every user, and gives you the email address directly.
Against: the highest-friction option. Users have to invent and remember a password, which means abandoned signups, forgotten-password flows, and the security burden of storing credentials properly.
Verdict: fine as a fallback, poor as the only option in 2026. If you offer it, at least don’t demand a password at signup — see magic links below.
Magic links (passwordless email)
For: no password to invent, no password to store, no reset flow. Sign-in and sign-up become the same action, which removes a genuinely confusing choice from your front door.
Against: it puts a mail round-trip in the middle of your funnel. If delivery is slow or the mail lands in spam, you’ve lost the user at the moment of highest motivation. Also awkward when someone signs up on their phone but works on a laptop, and it makes your email deliverability a load-bearing part of authentication.
Verdict: excellent when your transactional email is genuinely reliable, and a liability when it isn’t. Test the delivery time before committing.
Google sign-in
For: the highest-converting option for most SaaS. One tap, no password, verified email address, and near-universal coverage among business users.
Against: a dependency on Google, and users who later can’t remember which method they used.
Verdict: if you offer one social option, offer this one.
GitHub sign-in
For: for developer tools, it’s often the preferred option — it signals you’re built for their world, and it may carry authorisation scopes you need anyway.
Against: meaningless to non-technical users, and a wasted button on their signup screen.
Verdict: essential for developer-facing products, pointless otherwise. If you’re also shipping a CLI, this pairs naturally with your token flow.
Microsoft / work accounts
For: a large share of business users live in Microsoft accounts, and for B2B products selling into enterprises this is frequently more relevant than Google.
Against: more setup complexity, and it starts pulling you toward tenant and admin-consent considerations.
Verdict: worth it if you sell to companies rather than to individuals.
Facebook sign-in
For: broad consumer reach, particularly outside tech-centric audiences.
Against: meaningfully declining trust for anything business-related, and privacy-conscious users actively avoid it.
Verdict: consumer products with a mainstream audience, maybe. B2B SaaS, no.
SSO / SAML
Not a sign-up method so much as an enterprise requirement. It arrives when a large customer’s security team asks for it, and it is entirely reasonable to build it then rather than in advance.
How many to offer
More options is not obviously better. Beyond a certain point they create a specific problem: the returning user who can’t remember which one they used, tries a different button, and ends up with a second account and an empty workspace.
A reasonable default for most SaaS:
- One primary social option matched to your audience — Google for general business, GitHub for developer tools, Microsoft for enterprise.
- One email-based fallback — ideally magic link — for people who won’t or can’t use the social one.
Two buttons. That’s usually the right number.
If you do offer several, link accounts by verified email address so the same person landing via a different method arrives in the same account. This single implementation detail prevents most duplicate-account support tickets.
The bigger lever: what you ask for alongside it
The auth method matters less than the total number of things you demand before someone sees value. A one-tap Google sign-in followed by a six-field onboarding form is not a low-friction signup.
- Don’t ask for company size, role, or phone number at signup. Ask in-product, later, when the user has a reason to answer.
- Don’t require a credit card at the door unless your model genuinely needs the qualification (free plan vs free trial).
- Don’t block on email verification. Let people in and verify in the background where your risk model allows — a verification wall sends the user out of your product at the worst possible moment.
The full sequence is in the best ad conversion flow, which applies equally to organic traffic.
Measure it properly
Two things worth knowing that most teams don’t track:
- Conversion rate per method. Not just how many chose each, but what share of people who started each one finished. Magic-link drop-off in particular is invisible unless you measure the gap between “link sent” and “link clicked.”
- Activation rate per method. Sometimes the highest-converting signup produces the worst users. If one-tap signups activate at half the rate of email signups, that friction was doing qualification work.
And instrument the source before you optimise the method — you’ll want to know which acquisition channel produced each signup so the numbers mean something. That includes referral traffic, where the referrer needs to survive the whole auth round-trip: OAuth redirects are a classic place attribution silently breaks (how that’s handled).
The practical recommendation
For most SaaS: Google sign-in plus a magic link, no card, no extra fields, verification in the background, accounts linked by email. Add GitHub if you’re developer-facing, Microsoft if you’re selling to enterprises, and SSO when a customer’s security team asks.
Then spend the time you saved on the empty-state problem, which costs more activated users than any auth decision.
FAQ
Is magic link better than password for SaaS signup?
Usually, provided your transactional email is fast and reliable — it removes password creation, storage, and resets. The risk is putting an email round-trip in the middle of your funnel, so test delivery times first.
Should I offer social login for my SaaS?
One social option matched to your audience is worth it — Google for general business, GitHub for developer tools, Microsoft for enterprise. Offering many creates duplicate accounts when returning users forget which they used.
Does requiring email verification hurt conversion?
Blocking on it does, because it sends the user out of your product at the moment of highest motivation. Verifying in the background while they start using the product is usually the better trade unless abuse risk demands otherwise.
More conversion and growth guidance is in the growth & pricing hub.