Salesforce LWR Experience Cloud

1 What is Lightning Web Runtime (LWR)?

Lightning Web Runtime is Salesforce's next-generation framework for building Experience Cloud sites. According to the official Salesforce developer documentation, unlike Aura-based sites that render components dynamically at runtime, LWR takes a fundamentally different approach by pre-compiling and caching static content during the publish process.

Core Promises of LWR

2 Understanding LWR Architecture

How LWR Achieves Performance

The fundamental architectural difference between Aura and LWR lies in when content is generated. The Trailhead module on LWR explains this comprehensively:

3 Performance Benefits Explained

Why LWR is Faster

The performance gains in LWR are real and measurable, stemming from several architectural decisions documented in the Salesforce Help article on LWR basics:

1. Static Content Generation - Pages are generated at build time, not runtime
2. CDN Distribution - HTTP/3 protocols serve content from edge locations globally
3. Reduced Server Load - No dynamic component rendering per request
4. Optimized Caching - All static resources are HTTP cacheable with long TTLs

4 Critical Limitations Architects Must Know

This is where marketing diverges from reality. Based on real-world implementation experiences with enterprise deployments (78,000+ members, 120+ audience segments), here are the limitations that will impact your architecture decisions. The official LWR limitations documentation covers some of these:

1. Record Pages: No Generic Record Detail Page

Unlike Aura templates, LWR has no generic record pages. This means:

• Record-specific components (Record Detail, Record Header, Record Banner) can only be used on object-specific pages
• You cannot display record details on a regular site page like you could in Aura
• If you want a "My Account" page showing user account details, you must create an Account-specific object page
• Creating a generic record display component requires building complex custom LWC

2. Audiences vs. Visibility: A Fundamental Gap

Aura's robust audience targeting system is replaced by "Visibility Rules" in LWR, which is significantly more limited. The Salesforce Help article on visibility rules explains the available options:

3. Page Variations: Gone

In Aura, you could create multiple variations of a page for different audiences. In LWR, there are no page variations.

• Different themes or layouts require completely separate pages
• If one affiliation needs a blue theme and another needs gold, you need two separate pages
• Navigation between these pages must be handled through custom logic, flows, or separate navigation items
• Aura's automatic page variation selection based on audience is not available

4. CMS Collections: Limited Content Type Support

• News content type - Not fully supported in LWR
• Announcements - Cannot be displayed using standard LWR components
• Carousel component - Not available out-of-the-box; requires custom development

5. Navigation: Merge Fields Don't Work in URLs

This is a significant limitation that affects dynamic record navigation:

• Merge fields like {!User.FirstName} work for component content
• The same merge fields do not work in dynamic URLs
• Creating a "My Account" link that navigates to the user's specific account record requires custom workarounds

6-7. Missing Components and CSS Changes

• Record Detail, Carousel, some CMS display components missing
• Site-wide CSS editor is not available
• CSS must be migrated to sfdc_cms__styles folder in DigitalExperienceBundle metadata
• Must use --dxp styling hooks for consistent branding

5 Migration Considerations and Challenges

Component Migration

The most significant migration effort involves components. According to the Salesforce migration considerations guide:

• Aura components cannot run in LWR - Period. They must be rebuilt as LWC.
• LWC components may need modifications for LWR-specific features
• Out-of-the-box Aura components may not have LWR equivalents

URL Structure

• LWR sites don't use the /s/ URL segment by default
• Plan URL redirects carefully to preserve SEO and bookmarks
• Audit all internal and external links

Page Layout Conversion

• Convert to Flexible Layouts
• Plan for creating separate pages where page variations were used
• Design custom navigation logic for audience-specific pages

6 When to Migrate: A Decision Framework

7 Practical Workarounds and Solutions

For Audience Targeting

Implement a custom visibility solution:

1. Create component variations instead of page variations
2. Use Expression-Based Visibility (Summer '23+) for enhanced LWR sites
3. Build custom LWC that checks user attributes and conditionally renders content
4. Consider using Flows for complex audience logic

For Dynamic Navigation

1. Create intermediate redirect pages
2. Build custom LWC components that query record IDs via Lightning Data Service
3. Implement programmatic navigation using lightning/navigation API

For Missing Components

Develop a reusable component library:

• Generic Record Display component
• Custom Carousel component
• CMS Content Display for unsupported types
• Dynamic Navigation Menu component

8 Strategic Recommendations for Architects

1. Conduct a Thorough Assessment

Before committing to LWR migration:

• Inventory all Aura components in your current site
• Document audience segmentation requirements
• List all page variations and their purposes
• Identify CMS content types in use
• Map dynamic navigation requirements

2. Plan for Custom Development

Budget for building custom components to replace missing functionality:

• Generic record display components
• Custom navigation solutions
• Carousel and content display components
• Visibility/audience management logic

3. Consider a Hybrid Approach

For large existing sites, as recommended by LaunchPad Lab's migration guide:

• Build new features on LWR
• Maintain existing Aura site for complex functionality
• Gradual migration as LWR matures with each release

4. Stay Current with Releases

Salesforce enhances LWR with each release. Key recent improvements from the Salesforce Release Notes:

• Expression-Based Visibility (Summer '23)
• Enhanced CMS workspaces (Winter '25)
• Partial deployment capabilities
• New standard components

5. Document Your Decisions

Create an Architecture Decision Record (ADR) documenting:

• Why you're migrating (or not)
• Known limitations and accepted risks
• Custom development requirements
• Timeline considerations