The Salesfor Winter ’25 Release dropped some impressive upgrades this fall, but one game-changing feature is stealing the spotlight: Local Development for Lightning Web Components (LWCs). This capability now allows developers to preview, test, and iterate on their components in real-time, directly from their local machine, significantly accelerating the development workflow. If slow testing cycles have ever made you want to scream into the void, this update is here to save your sanity.
Let’s explore how Local Development for LWCs works, its benefits, and how you can start using it today.
What Is Local Development for LWCs?
Local Development enables developers to work on Lightning Web Components in an environment hosted on their own machines. Unlike the traditional process, which requires deploying changes to a Salesforce org to test and preview, this feature offers rapid-feedback loop for building components.
By spinning up a lightweight local development server, Salesforce provides developers with a browser-based preview of their components. This environment is designed to mimic Salesforce’s user interface and behaviour, allowing you to develop and test components with a high degree of fidelity to the final application.
Why Local Development Is a Game-Changer
For years, building and testing LWCs involved deploying them to a Salesforce org, switching between the development environment and browser, and refreshing pages after every update. This workflow was not only tedious but also slowed down iteration cycles. The Winter ’25 release addresses these pain points by providing a seamless local experience.
Key Benefits:
- Real-Time Feedback: See your changes in real-time as you edit your LWC code. No need to deploy for every small tweak.
- Improved Productivity: Work faster by removing the deployment step and focusing on what matters—building great features!
- Streamlined Debugging: Isolate and troubleshoot issues in a controlled, local environment without external dependencies.
- Enhanced Collaboration: Team members can work on the same project locally, share their changes, and avoid conflicts that arise from working in a shared Salesforce org.
- Optimize Shared Resources and Save Time: Local development is particularly valuable in environments where org resources are shared or limited. It reduces API usage and speeds up workflows.
Now, Let’s Set Up Local Dev!
For now, this feature is only available through the Salesforce command-line interface (CLI) ; there is another LWC Local Development Server, which has limited testing and previewing capabilities. To run a real-time preview for your app or site, ensure you:
Install the Local Dev Plugin
In your terminal, run this CLI command for your project:
sf plugins install @salesforce/plugin-lightning-dev
Enable Local Dev
Before you can use Local Dev for an app or site, you have to enable it for your Salesforce Sandbox org or scratch org. To turn on this beta feature for your Sandbox org:- Open Setup
- In the Quick Find box, enter
Local Dev and then select - Select Enable Local Dev (Beta) to turn on the feature for all org users.
Scratch Org
To enable Local Dev for your scratch org:- In your SFDX project, open the file
config/project-scratch-def.json . - In the settings section of the file, add the key
“enableLightningPreviewPref” and set it totrue , like this:
{
“orgName”: “My Company”,
“edition”: “Developer”,
“features”: [“EnableSetPasswordInApi”],
“settings”: {
“lightningExperienceSettings”: {
“enableS1DesktopEnabled”: true,
“enableLightningPreviewPref”: true
},
“mobileSettings”: {
“enableS1EncryptedStoragePref2”: false
}
}
}
Run a Real-Time Preview
To preview a Lightning app, run this command in your terminal:
sf lightning dev app
To preview an Experience Cloud LWR site, run this command:
sf lightning dev site
Before you can run Local Dev for an Experience Cloud LWR site, you have to finish these setup steps:
- After Local Dev is enabled for your org, publish your Experience Cloud LWR site.
- Set your site’s base path to /. To learn how to configure site paths, see Salesforce Help: Add a Custom URL
Features of the Local Development Environment
The local server is built to provide an authentic Salesforce-like experience. Here are some of its notable features:
- Simulated Salesforce Context: The local environment includes base Lightning components, event-handling capabilities, and a UI consistent with Salesforce’s look and feel.
- Dynamic Theming: Test your components under different Salesforce themes, such as Lightning Experience or Salesforce Mobile.
- Cross-Browser Compatibility: Ensure your components work seamlessly across various browsers.
- Error Debugging: Use browser developer tools to debug your code with detailed error messages and stack traces.
Limitations to Consider
- Platform-Specific Features: Features like App Builder or Flows cannot be simulated locally.
- Setup Requirements: New developers might need time to configure the environment and understand its capabilities.
- Implementing
<lightning-button></lightning-button> resulted in ‘404: Could not find module with specifier “lightning/button”‘ error
Some Final Thoughts
The Local Development feature for LWCs in Winter ’25 empowers developers to build faster, iterate quicker, and debug more effectively. By bringing the development and testing processes closer together, Salesforce is addressing a major bottleneck in LWC development workflows.
Whether you’re prototyping a new component, fixing a bug, or building an entire library of reusable UI elements, Local Development makes the process smoother, more intuitive, and more efficient. For teams working in agile environments or under tight deadlines, this is a must-have tool.
After diving into the Winter ’25 release and exploring the standout features which we called out and were excited for, we’re confident that Local Development for Lightning Web Components is a game-changer for boosting developer productivity. With real-time feedback and rapid iteration, this feature sets the stage for faster innovation and higher-quality components. Are you looking to streamline your Salesforce development process? Let’s chat!
Author: Faisal Anwar Mohammed
Developer at Lane Four
Let's chat!
