Let’s face it–product managers today expect more from content builders. They don’t just want functionality for end-users; they want flexibility for developers.
Whether designing a stunning email marketing campaign or creating a landing page, the demand for drag and drop functionality is at an all-time high.
That’s where embedding an email/page builder in your SaaS becomes a real lifesaver. Instead of end-users bouncing between your platform and third-party tools, you’re giving them everything they need in one seamless experience, i.e., within the host application—the kind of feature that will make people’s lives easier.
In this quick guide, we’ll walk you through four key sections:
Choosing the right email/page builder for your application
Embedding a builder like Unlayer into your SaaS without breaking a sweat
Extending its functionality to match your product’s unique use cases and user needs
Best practices for smooth integration
So, let’s dive in and make your host application a whole lot more powerful.
How to Choose the Right Email/Page Builder for Your SaaS?
With tons of options out there, you might be wondering which email/page builder to choose. Before you dive deep into the setup, here are a few things you really should look for:

1. Customizability
Can you tweak it to match your host application’s branding? Add your own tools or features? This functionality is vital if you’re going for that polished, native feel.
2. Ease of integration
The last thing you want is a content editor that turns your developers into part-time firefighters. Therefore, look for a solution with a ready-to-use code, solid documentation, and a fast setup.
3. Extensibility
Will your selected no-code builder grow with you? You might start with basic templates, but what if your users want custom blocks or more advanced functionality down the line?
4. Drag and drop interface
This is a non-negotiable. Today’s users expect that smooth, no-code, drag and drop feel.
One of the most popular (and developer-friendly) options out there is Unlayer. It checks all the boxes discussed above as it is simple to embed, easy to customize, and fully extendable. Whether you’re a marketing platform like Mailchimp or a CRM like Hubspot, it fits in nicely.
Now, depending on your SaaS product’s offering, you might be wondering:
Should I use a dedicated email builder or a SaaS landing page builder?
If you are a platform focused on creating and distributing marketing assets like emails, newsletters, and other related content, then a full-featured email builder is the way to go.
But if you want to build funnels, lead capture pages, or microsites, then a landing page builder (or a hybrid that supports both) will make more sense.
Some SaaS tools need both, and that’s where a flexible tool like Unlayer really shines because it comes with a built-in email, landing page, popup, and document builder.
Embedding the Email/Page Builder in Your SaaS App
Now that you’ve picked an email/page builder (we’ll assume you’re going with Unlayer for this example), let’s discuss how to embed it into your platform.
Step 1: Add the JavaScript snippet
First off, you need to add the Unlayer JavaScript snippet to your web app. This will load everything required to run the editor.

If you're using a modern JavaScript framework, you’re covered too. Unlayer has official components available via npm for:
Each one has its own integration guide, complete with code samples to drop right into your component setup.
Step 2: Add a container for the editor
Next, add a blank div where you want the builder to appear:

Pro tip: Make sure this container is at least 1024px wide and 700px tall. That gives the editor enough breathing room to work properly, especially on larger screens.
Step 3: Initialize the editor
Now comes the fun part—initializing the editor inside the container you just created:

You can configure a ton of things here—like setting the default locale, passing in user info, defining merge tags, adjusting the UI, adding custom blocks, fonts, or tools. Unlayer gives you full control.
Step 4: Deploy to production
Before you go live, make sure to:
Add your domain(s) to the Allowed Domains list in your project settings.
Always pass your projectId when initializing the builder in production.
Extending the Email/Page Builder for a Custom Experience
At this point, you’ve got a fully functional email/page builder in your SaaS, and it’s live in your host application. But we’re just getting started.
Let’s look at how you can extend the functionality of the editor to create a custom experience that fits your product like a glove.
What is a custom tool?
A custom tool is a user-defined element that acts just like a built-in drag and drop block. You can design these components tailored to your specific brand needs.

Think beyond text, buttons, or images. You could build:
Pricing tables
Interactive maps
Social feeds
Dynamic forms
Example: Creating a Map Tool using Google Maps
Let’s say you want to add a Map block to your email or page templates, powered by Google Maps Static API. Here’s how to create a custom "Map" tool from scratch.
Step 1: Define the tool (in a custom JS file)
Create a file called custom.js and register your tool like this:

Step 2: Load the custom JS file in the builder init code
Once your tool is ready, include it in your unlayer.init() configuration like this:

Once initialized, the custom Map Tool will show up right inside the builder with its own icon.

Users can drag it into their design, customize map coordinates, zoom level, and map type—all with a simple side panel UI. The builder handles rendering, and your app gets the HTML when exported.
Watch it in action 🎥
Want a quick walkthrough? Check out this video tutorial, where we build and integrate a custom tool step-by-step—from defining the tool to seeing it live in the builder. It's perfect if you're more of a visual learner or just want to speed-run the setup.
https://www.youtube.com/watch?v=ZqYzdvnyL5w
Best Practices for a Smooth Integration of Email/Page Builder
After getting your builder up and running with custom tools and all, it is time to talk about what it takes to keep things smooth, secure, and scalable as you grow.
Here are some key best practices to keep in mind when integrating email/page builder in your SaaS application.
1. Security considerations
Don’t skip the security layer. When you embed a content builder, you’re potentially handling sensitive user data, especially if it ties into your CRM, ESP, or CMS.
Allowed domains: Limit where your builder can be loaded via Unlayer’s “Allowed Domains” settings.
Data privacy: If users save or import templates, make sure they’re encrypted and in accordance with privacy laws (think GDPR, CCPA, etc.).
2. White-labeling
If you’re offering a white-label email builder experience, go the extra mile:
Use Unlayer’s appearance config to customize UI colors, fonts, and branding.
Hide advanced features your users don’t need to keep things simple.
Replace the default Unlayer branding with your own to create a seamless brand experience and present this tool as your own to end-users.
3. Smart template management
Let your users create, save, and re-use templates without friction:
Implement role-based access: marketers, designers, admins—they may all need different permissions.
Integrate the export/import API to store and load templates from your backend.
Version saved templates, so users can go back to previous iterations without stress.
4. Mobile responsiveness and accessibility
Your builder might live on a desktop, but your email and landing page designs will be opened on phones 83% of the time. Make sure to:
Test exported designs across devices and email clients.
Customize or enforce mobile-first layouts in templates.
Use accessible color contrasts and semantic HTML to stay inclusive and compliant.
5. Error handling and version control
Even drag and drop magic can break sometimes.
Add graceful error messages if something goes wrong when loading or saving.
Log design export failures and validate template data before rendering or sending.
Final Thoughts: Build vs. Buy – And What’s Next
So, let’s face the imminent question: should you build your own editor from scratch or integrate a white-label tool like Unlayer SDK?
In most cases, embedding a proven email/page builder in SaaS saves you:
Months of development time
Maintenance overhead
UX headaches
Security implications
Unless your product is 100% design-centric and you have a full-time dev team dedicated to it, embedding a no-code builder like Unlayer makes more sense.
The best part? Your end-users can easily spend more time designing engaging emails and landing pages within the host application. That means fewer tool switches, more engagement, and better retention.
🚀 Ready to try it?
If you’re thinking, “This sounds like something our SaaS users would love” you’re probably right.
✅ Try integrating Unlayer into your dev or staging environment
🎯 Or book a demo with our team to explore how it fits into your roadmap