If you’re building on the ServiceNow platform, there are two fundamentals you need to be aware of. The first is understanding which scripting and coding languages to focus on. The second, is to follow the ServiceNow development best practices.
These are the key to building scalable, maintainable, and modern business applications.
The platform has evolved significantly in recent years, and so have the technologies behind it.
Whether you're a new developer or a tech leader looking to hire a ServiceNow developer, this guide covers the seven core development languages and frameworks that matter most today.
What is ServiceNow Development?
ServiceNow development refers to the process of creating, customizing, and extending applications on the ServiceNow platform. This includes building workflows, designing user interfaces, automating tasks, and integrating with third-party systems.
ServiceNow is a cloud-based platform primarily used for IT service management (ITSM), but its capabilities now span customer service, HR, operations, and other enterprise functions. Developers use a variety of scripting languages and frameworks to create custom applications or modify out-of-the-box modules to better meet organizational needs.
Most of the work involves client-side scripting, server-side scripting, and front-end development using tools built into the platform. Unlike traditional software development, ServiceNow development is platform-specific, meaning developers must follow ServiceNow’s architecture and use its proprietary tools and APIs — including GlideRecord, UI Builder, and Flow Designer.
7 development languages for modern ServiceNow scripting
Here are the 7 development languages to know as you work with ServiceNow scripting.
1. JavaScript
If you're working in ServiceNow, JavaScript is non-negotiable. It's the primary scripting language used across the platform — both on the client-side and server-side. Whether you're writing a Business Rule, customizing a form with a Client Script, or building a Script Include for reusable logic, you're writing JavaScript.
Starting with the Washington DC release, ServiceNow’s server-side JavaScript engine supports ECMAScript 2021 (ES12), giving developers access to modern features like let and const, arrow functions, optional chaining, and destructuring. This allows for more efficient, readable, and maintainable code — while maintaining compatibility with older scripts.
Here’s where JavaScript shows up most often in ServiceNow development:
Client Scripts
Business Rules
Script Includes
UI Policies & Actions
2. GlideRecord (JavaScript API)
GlideRecord is ServiceNow’s server-side API for working with the platform’s database. It’s essentially how developers perform CRUD operations (Create, Read, Update, Delete) on ServiceNow tables using JavaScript — but without needing to write traditional SQL.
If JavaScript is the language, GlideRecord is the way you talk to the database. It’s a built-in object that gives you powerful methods to query records, loop through them, and manipulate data within scripts.
Here’s where GlideRecord is most commonly used:
Business Rules
Script Includes
Scheduled Jobs
Flow Designer
This script finds all high-priority incidents and updates their state — no SQL required.
3. GlideAjax + AJAX
Enabling asynchronous communication between the client and server is achieved through GlideAjax — using AJAX under the hood. It allows you to call server-side logic from a client script without refreshing the page, which is essential for building responsive, dynamic user experiences.
Think of GlideAjax as a secure, structured way to fetch data or trigger server-side actions based on something a user does in the browser.
Common use cases include:
Fetching related data
Validating input
Triggering background logic
4. AngularJS
AngularJS is the JavaScript framework used to build and customize widgets within the Service Portal, ServiceNow’s front-end framework for building user-friendly, self-service experiences.
While AngularJS has been sunset by Google, it’s still fully supported in ServiceNow’s platform for widget development. If you're creating custom portals or interfaces, especially for end users or customers, you’ll be working with AngularJS alongside HTML, CSS, and server-side scripting.
AngularJS is used in:
Custom widgets
Data binding
REST integrations
Conditional rendering
5. HTML + CSS + Bootstrap
When building modern user interfaces in ServiceNow — especially in the Service Portal — you’ll rely on a combination of HTML, CSS, and Bootstrap to create responsive, branded, and user-friendly layouts.
While JavaScript and AngularJS handle logic and interactivity, HTML and CSS control the structure and visual design of widgets, pages, and forms. ServiceNow includes Bootstrap by default, giving developers a powerful, mobile-friendly framework for grid layouts, buttons, typography, and form styling.
You’ll use these technologies in:
Custom widget templates
Portal branding and theming
Responsive layouts
UI tweaks and overrides
6. TypeScript
TypeScript is a superset of JavaScript that adds static typing, better tooling, and enhanced error detection — and it's starting to play a growing role in advanced ServiceNow development, particularly for enterprise-scale integrations and external apps.
While the core ServiceNow scripting engine still relies on JavaScript, TypeScript is increasingly used in custom integrations, external front-end applications, or tools built around ServiceNow’s REST APIs. It’s also helpful when building reusable components or SDK-style modules that interface with the platform.
Where TypeScript shows up:
Custom front-ends
Integration tooling
Testing and refactoring complex logic
Even though ServiceNow doesn’t (yet) run TypeScript natively inside the platform, it’s becoming a go-to language for developers building around the platform, especially in hybrid or micro-frontend architectures.
7. React
React is the front-end framework powering the Next Experience UI and Workspace applications in ServiceNow — the future of modern, enterprise-grade user interfaces on the platform.
While you don’t build directly in React when using UI Builder, it’s important to understand that React is the underlying engine for these newer experiences. And if you’re developing custom components for Workspace, or extending the platform with the ServiceNow Design System, you’ll be working with React code directly.
Where React is used:
Next Experience (Polaris UI)
Workspace
UI Builder custom components
Custom portals or apps built outside the platform
Scripting languages for those working in legacy environments
While modern ServiceNow application creation focuses on JavaScript, AngularJS, and React, you may still encounter legacy technologies like Jelly (an XML-based scripting language) and jQuery in older implementations. These are used in UI Macros, UI Pages, and early customizations within the Classic UI. If you’re maintaining or upgrading an older instance, it’s helpful to recognize these patterns — but for new development, they’re largely obsolete.
Ready to learn the right languages — the right way?
One of the most effective ways to learn ServiceNow development languages is by working with experts who build on the platform every day. At DevSquad, we don’t just deliver fully customized ServiceNow solutions — we also offer hands-on knowledge transfer and training as part of your build.
After your ServiceNow instance is launched, we help your internal team understand exactly how it was built — including the scripting languages used — so you can confidently maintain and extend your system moving forward.
Looking to launch or modernize your ServiceNow instance?Work with DevSquad and build with the best.
