When Lightning Web Components launched in Spring ‘19, Salesforce positioned it as the modern standard and Aura as the legacy framework being maintained but not evolved. Seven years later in 2026, that positioning is more concrete than ever. New platform capabilities — dynamic forms, screen flow embedding, Slack components, Einstein features — all target LWC exclusively.
If you are still building new Aura components, you are building on a platform that is moving away from you. This guide gives you the practical knowledge to migrate existing components and stop creating new technical debt.
Why LWC Performs Better: The Architecture Reason
The performance difference between LWC and Aura is not a marketing claim — it has a specific technical cause.
Aura runs on a custom JavaScript framework. When a page loads an Aura component, the browser must download and execute the entire Aura framework runtime before it can render anything. LWC is built on the W3C Web Components standard, which modern browsers implement natively — no framework download required.
Salesforce’s own benchmarks show LWC components loading roughly 3x faster than equivalent Aura components in Lightning Experience. On slow connections — mobile sales reps, international users — this difference is immediately perceptible.
Feature Comparison Table
LWC Advantages
| Feature | LWC | Notes |
|---|---|---|
| Data binding | {propertyName} | Cleaner syntax |
| Event up | CustomEvent (standard W3C) | Browser standard |
| Event down | @api properties | Declarative |
| Wire service | @wire (full support) | More adapters |
| Dynamic components | lwc:dynamic | Simpler |
| Slots | <slot> (W3C standard) | Standard compliant |
| Shadow DOM | Native + synthetic | More encapsulated |
| Screen flows | Full embed support | Full support |
| Slack / Mobile | Full support | LWC only |
| New features | Active development | Critical difference |
Aura Legacy
| Feature | Aura | Notes |
|---|---|---|
| Data binding | {!v.propertyName} | Verbose syntax |
| Event up | fire / aura:method | Custom framework |
| Event down | Attributes | Declarative |
| Wire service | @wire (limited) | Fewer adapters |
| Dynamic components | $A.createComponent() | Complex API |
| Slots | <aura:set> | Non-standard |
| Shadow DOM | Locker Service (emulated) | Less encapsulated |
| Screen flows | Limited support | Restrictions |
| Slack / Mobile | Not supported | Dead end |
| New features | Maintenance only | No investment |
Scenario: A large org has 80+ Aura components built over 5 years. A new Salesforce feature — Dynamic Forms — only works on LWC. The team tries to add Dynamic Forms to a record page, but a custom Aura component on the same page blocks the feature entirely. The business cannot use a core platform capability because of legacy component debt.
Prioritize migrating Aura components that appear on record pages where new platform features will be deployed. Start with leaf components (those with no Aura children) on those pages, migrate them to LWC one at a time, and use Lightning Message Service as the communication bridge between any remaining Aura parents and the new LWC children during the transition.
Migration Checklist: Common Code Equivalents
Component Attributes / Properties
Aura
<aura:attribute name="recordId" type="String" />
<aura:attribute name="title" type="String" default="My Component" />LWC
import { LightningElement, api } from 'lwc';
export default class Component extends LightningElement {
@api recordId;
@api title = 'My Component';
}Calling Apex Methods
Aura (Callback)
({
doInit: function(component) {
var action = component.get('c.getAccountData');
action.setParams({ accountId: component.get('v.recordId') });
action.setCallback(this, function(response) {
if (response.getState() === 'SUCCESS') {
component.set('v.account', response.getReturnValue());
}
});
$A.enqueueAction(action);
}
})LWC (Wire)
import { LightningElement, api, wire } from 'lwc';
import getAccountData from '@salesforce/apex/AccountController.getAccountData';
export default class Component extends LightningElement {
@api recordId;
@wire(getAccountData, { accountId: '$recordId' })
account;
}LWC (Imperative)
import getAccountData from '@salesforce/apex/AccountController.getAccountData';
export default class Component extends LightningElement {
@api recordId;
account;
connectedCallback() {
getAccountData({ accountId: this.recordId })
.then(result => { this.account = result; })
.catch(error => { console.error(error); });
}
}Component Events (Parent-Child Communication)
Aura Events
({
handleClick: function(component) {
var event = component.getEvent('recordSelected');
event.setParams({ recordId: component.get('v.recordId') });
event.fire();
}
})LWC CustomEvent
handleClick() {
this.dispatchEvent(new CustomEvent('recordselected', {
detail: { recordId: this.recordId }
}));
}
// Parent template listens:
// <c-child-component onrecordselected={handleRecordSelected}></c-child-component>Conditionals and Iteration
Aura
<aura:if isTrue="{!v.isVisible}">
<p>Visible content</p>
</aura:if>
<aura:iteration items="{!v.items}" var="item">
<p>{!item.name}</p>
</aura:iteration>LWC
<template lwc:if={isVisible}>
<p>Visible content</p>
</template>
<template for:each={items} for:item="item">
<p key={item.id}>{item.name}</p>
</template>The key attribute in LWC for:each iterations is mandatory, not optional. Missing it causes a runtime warning and degrades rendering performance because the framework cannot efficiently diff list changes. Always use a stable, unique identifier — never use the loop index as the key.
Migration Strategy: Component by Component
Do not attempt to migrate an entire org at once. The correct approach:
Audit your Aura components — identify which are standalone and which depend on shared Aura events or app-level events. Standalone components migrate first.
Start with leaf components — components that have no Aura children. These have the fewest dependencies and lowest risk.
Replace Aura events with LMS — Lightning Message Service is the LWC-compatible replacement for application-level Aura events. Both Aura and LWC components can publish and subscribe to LMS channels, which makes it the communication bridge during migration.
Aura wrappers for slow migrations — you can wrap an LWC component inside an Aura component using
<c:myLwcComponent>. This lets you migrate the implementation to LWC while keeping the Aura parent temporarily.Do not rewrite logic, translate syntax — LWC and Aura call the same
@AuraEnabledApex methods. Your server-side logic does not change; only the client-side syntax.
What Aura Does That LWC Cannot (Yet)
I want to be honest about the gaps, because migration guides that ignore limitations are not useful:
lightning:overlayLibraryfor custom modals — LWC haslightning-modalas the replacement but some advanced modal behaviors still differ- Some legacy base component events — certain Aura-specific event names do not have direct LWC equivalents
force:navigateToURL— in LWC you use theNavigationMixin, which is actually more capable but requires a refactor
For the vast majority of enterprise components, these gaps do not apply. The migration is straightforward.
The ROI Case for Migration
The business case for migrating to LWC is not purely technical. It includes:
- Hiring — developers who know modern LWC are more available than Aura specialists. Training new developers on Aura in 2026 is training them on a dead-end skill.
- Support — Aura bugs are fixed, but new features and performance improvements ship exclusively to LWC.
- Platform features — Dynamic Forms, Einstein copilot integration, Slack deployment — all require LWC. (Note: Screen Flow embedding is available in both LWC and Aura via
<lightning:flow>, but new Flow-related enhancements target LWC first.) - Performance — faster pages have measurable business impact, particularly for field sales users on mobile.
I recommend scheduling at least one LWC migration sprint per quarter until you are below 10% Aura component coverage. At that point, the remaining Aura components are likely complex enough to warrant a dedicated migration project rather than iterative sprints.
What is the most complex Aura component you are dreading migrating to LWC? I am curious whether the challenge is usually the event architecture or the Aura-specific APIs.
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