Deep customization for your authentication experiences

You've spent months perfecting your product's design. Every color, button, and animation is deliberate—an extension of your brand's identity.

Then your users click "Sign In" … and land on a generic login page that looks nothing like your app.

Moments later, they get a verification email from an unfamiliar domain. Gmail flags it as suspicious. They hesitate—maybe even abandon the flow. That's the moment trust breaks. And trust, in authentication, is everything. It's often your brand's handshake, the first impression of reliability, professionalism, and safety.

Scalekit gives you deep control over every touchpoint to make that handshake unmistakably yours.

What was already there: Login page customization

Your login page should look and feel like your app—not an out-of-the-box template. As a refresher, with Login Page Branding, you can customize:

Visual identity

• Upload your logo and favicon
• Match your brand colors with full color picker control
• Adjust border radii (small, medium, or large) for buttons and containers
• Control logo positioning (inside or outside the login box)
• Set logo and header alignment (left, center, or right)

Layout control

• Position social login buttons exactly where you want them
• Configure background styles using full CSS shorthand—solid colors, gradients, images, patterns, or combinations with position, size, repeat, origin, clip, and attachment properties
• Apply background images with flexible positioning (center, top, left) and sizing (cover, contain, repeat)

Newly launching: Advanced styling

• Use CSS background shorthand for complete control: url('https://example.com/image.jpg') center center/cover no-repeat
• Create gradient backgrounds: linear-gradient(135deg, #4568DC, #B06AB3)
• Set fallback colors for images: #f5f5f5 url('image.jpg') center/cover
• Design tiled patterns with custom positioning and repeat rules

Whether your design language is minimalist or expressive, Scalekit's customization tools let you control every visual element from the very first pixel. Preview changes instantly in your dashboard under Customization → Branding—no code required.

What was already there: Bring your own email delivery infrastructure

Scalekit provides email delivery out of the box, but you can integrate your own email provider for complete control over sender domains, deliverability, and compliance. Use your own SMTP provider—SendGrid, Amazon SES, Postmark, or any SMTP service.

That means:

• Emails come from your verified domain
• You maintain your sender reputation
• Your messages pass enterprise compliance checks
• You get deliverability insights in your existing analytics stack

Setup takes minutes: enter your SMTP host, port, credentials, and sender info. Everything is encrypted, secure, and under your control. Because your brand deserves to own its communication end to end.

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Newly launching: Design custom email templates that speak your voice

But now, you can go ahead and make sure each auth mail is crafted in your own voice and with your message.
After all, default templates get the job done. Custom templates get your message heard.

Scalekit's template engine lets you rewrite every authentication email—from magic links to password resets—in your own tone and style. You can:

• Edit subject lines, HTML, and plain text versions
• Use JET syntax for logic, loops, and conditionals
• Inject dynamic variables at runtime (like {{first_name}}, {{company_name}}, or {{onboarding_resources}})
• Send multipart emails—HTML for modern clients, plain text for legacy ones
• Control every aspect of the message structure and content

All accessible under Emails → Templates in your dashboard. Full control. No compromises.

What you'll need

• For login page branding: logo and favicon files, color codes, CSS background properties, and layout preferences
• For custom email delivery: SMTP credentials, verified sender domain, and display name
• For custom templates: your HTML designs and variable mappings

Start today

Everything you need to deeply customize your experience—login pages with full CSS control, custom email delivery, and personalized templates—is live now.

Check out the guides on Login Page Customization and Email Customization, or reach out to our team to walk through your setup.

FAQs

Why is brand consistency critical for B2B authentication workflows?

Maintaining brand consistency throughout the login process is vital for establishing user trust. When enterprise users encounter generic or mismatched authentication pages, it creates friction and security concerns. Scalekit enables you to match every visual element, from logos to CSS background styles, ensuring a seamless transition from your application to the identity provider. This unified experience reduces bounce rates and reinforces your brands professional image, which is essential for building long-term reliability with high-value B2B clients and their security-conscious IT departments.

How does Scalekit allow for advanced CSS styling on pages?

Scalekit provides granular control over the login interface using CSS shorthand for complex background configurations. Engineering teams can implement gradients, tiled patterns, and responsive background images directly through the dashboard. This flexibility allows for high-fidelity designs that incorporate specific brand attributes like custom border radii and precise logo positioning. By leveraging these advanced styling tools, you can ensure that the initial authentication handshake reflects the same quality and design language as your primary application without writing custom frontend code for every identity flow.

What are the security benefits of using custom SMTP providers?

Integrating your own SMTP provider like SendGrid or Amazon SES ensures that authentication emails originate from your verified domain. This significantly improves email deliverability and prevents messages from being flagged as suspicious by enterprise security filters. From a CISO perspective, owning the communication infrastructure allows for better compliance tracking and sender reputation management. Scalekit encrypts these credentials and manages the delivery logic while giving you full visibility into the analytics. This architecture ensures that your authentication communications meet the rigorous security standards required by modern enterprise customers.

Can developers use dynamic data within custom email templates?

Yes, the Scalekit template engine supports JET syntax, which allows for the injection of dynamic variables at runtime. This capability enables you to personalize messages with user-specific data like first names, company names, or custom onboarding resources. Beyond simple substitution, the engine supports logical operations and conditionals to tailor the content based on the users context. This level of customization ensures that critical communications like magic links and password resets are informative and contextually relevant, ultimately improving user engagement and reducing support overhead for your engineering teams.

How does Scalekit handle email compatibility across different mail clients?

Scalekit supports the delivery of multipart emails, which include both HTML and plain text versions of your messages. This ensures that your authentication emails are rendered correctly across a wide range of mail clients, including modern desktop applications and legacy systems. By providing full control over the message structure, you can maintain a consistent visual identity in the HTML version while ensuring accessibility and readability in the text-only version. This comprehensive approach to template management ensures that every user has a reliable and professional experience regardless of their specific software environment.

What visual elements can be customized on the login interface?

Scalekit offers extensive customization options including logo uploads, favicon settings, and full color picker control for brand alignment. You can adjust the layout by positioning social login buttons and configuring header alignments to match your UI patterns. Additionally, the platform allows for fine-tuning of container aesthetics, such as border radii and logo placement. These features enable developers to build an authentication experience that is indistinguishable from their internal application pages. Instant previews in the dashboard allow for rapid iteration without needing to deploy new code or modify backend services.

Why should enterprises prioritize custom domain email delivery?

Custom domain delivery is essential for passing enterprise compliance checks and maintaining a strong sender reputation. When emails come from an unfamiliar domain, it can trigger security warnings or result in messages being quarantined by corporate firewalls. By using your own infrastructure through Scalekit, you ensure that every handshake is recognizable and trusted by the recipient. This setup also provides you with detailed deliverability insights within your existing analytics stack. For CISOs, this control is a prerequisite for meeting the strict data privacy and security requirements of large-scale B2B organizations.

What syntax is used for logic in email templates?

Scalekit utilizes the JET syntax within its email template engine to facilitate complex logic and conditional content. This allows engineering teams to create sophisticated email flows that include loops, if-else statements, and dynamic variable mapping. By using JET, you can programmatically change the content of an email based on the user profile or the specific authentication event. This flexibility is crucial for B2B applications that need to deliver personalized experiences to different customer segments while maintaining a single, scalable codebase for all authentication-related communication and user engagement workflows.

How do I get started with Scalekit customization?

Getting started with Scalekit customization is straightforward and requires no complex coding. Developers can access the branding and template settings directly through the admin dashboard. For login pages, you will need your logo files, brand color codes, and any specific CSS background properties you wish to apply. For email delivery, simply enter your SMTP credentials and verify your sender domain. Scalekit provides comprehensive guides for both login and email customization to help you walk through the setup process. This low-friction implementation allows you to enhance your brand experience and user trust immediately.

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