In this blog
The most common Edge Delivery question we get is framed wrong: "should we move from AEM Sites to EDS?" treats them as successive versions. They are not — they are two delivery philosophies inside one family, and mature estates run both. The productive question is which of your surfaces belongs on which — so this comparison is built to answer exactly that.
Two philosophies, one family
AEM Sites is the governance machine: structured components, Multi-Site Manager, translation workflows, granular permissions, audit trails. Its promise is control at scale — forty sites, twelve languages, sixty authors, one coherent system. Its cost is weight: development in the full AEM stack, publishing through governed pipelines.
Edge Delivery Services is the velocity machine: documents become pages, blocks build in plain web tech, and everything serves pre-rendered from the edge. Its promise is speed at both ends — sub-second pages and same-day publishing. Its cost is intentional lightness: governance is thinner, structure is looser.
Neither philosophy is superior; they answer different pressures. The platform overview covers EDS mechanics; here we compare where each earns its place.
Side by side
| Dimension | AEM Sites | Edge Delivery Services |
|---|---|---|
| Page performance | Good when engineered well | 90–100 Lighthouse structurally |
| Publishing speed | Governed pipelines, hours–days | Minutes, preview → live |
| Authoring | Component editing, dialogs | Documents or Universal Editor |
| Governance | MSM, ACLs, workflows, audit | Light: sharing controls, preview gates |
| Translation at scale | Native workflows, vendor integration | Manual or custom tooling |
| Development | AEM component stack, Cloud Manager | Blocks: HTML/CSS/JS in Git |
| Developer onboarding | Months | Days–weeks |
| Experimentation | Via Target integration | Built-in, plus Target |
| Best-fit surfaces | Governed estates, portals | Marketing, blogs, campaigns |
Where Sites remains the right answer
Honesty about the incumbent: nothing in EDS replaces Multi-Site Manager's blueprint inheritance for a 40-site global estate, the translation pipelines feeding twelve locales, or permission models that mirror a regulated org chart. Logged-in experiences, deep integrations and structured-content operations with heavy reuse — ecosystems like ICICI Direct's — are built on exactly the machinery Sites carries and EDS deliberately omits. If your pain is coordination at scale, Sites' weight is not overhead; it is the product.
Where EDS changes the game
Two numbers recur in our EDS deliveries: Lighthouse scores in the 90s and publishing measured in minutes. For surfaces where those numbers are the business case — SEO-driven content fighting for Core Web Vitals rankings, campaign pages that must launch this week, marketing estates throttled by release cycles — EDS is not incrementally better; it is a different category of capability. Godrej Capital holds top scores under calculator-heavy interactivity; ICICI Home Finance went from developer-dependent publishing to same-day. The economics compound too: block development in plain web technologies runs faster and staffs easier than full-stack AEM component work — Asian Paints compressed delivery ~40% with AI-assisted block scaffolding on top.
The surface-by-surface framework
Score each surface on four questions:
- Does page speed move money here? (SEO rankings, paid-media landing conversion) → weight toward EDS
- Does publishing speed move money here? (campaign velocity, newsroom cadence) → weight toward EDS
- Does this surface need heavy governance? (multi-locale, regulated approvals, granular permissions) → weight toward Sites
- Is this experience deeply integrated or logged-in? → weight toward Sites/headless
Typical outcome for an enterprise estate: marketing site sections, blog and campaign pages migrate to EDS over two or three quarters; the governed corporate estate, portals and locale-heavy properties remain on Sites; both share Assets, analytics and Target. That is not a compromise — it is the architecture Adobe is building toward, and estates like ZS Associates that moved AEM → EDS surface-by-surface kept SEO and sanity intact precisely because the moves were incremental.
Coexistence mechanics that matter
- Decide content ownership per type. Product pages on Sites, campaign pages on EDS — avoid two-way syncing ambitions; shared Assets covers media
- One analytics and consent implementation spanning both, so measurement and compliance do not fork
- A shared design system expressed twice — Sites components and EDS blocks — with one source of visual truth
- Unified search and navigation so visitors never feel the seam
Deciding without regret
The failure modes are symmetric. Forcing governed, locale-heavy estates onto EDS recreates governance in duct tape; keeping fast-moving marketing surfaces on Sites pays the weight tax forever and blames the platform. Walk your site inventory with the four questions, move the obvious EDS candidates first, and let results fund the roadmap. For the estate-mapping exercise run with people who operate both models daily, talk to a consultant — the benefits analysis quantifies what the moved surfaces typically gain.
Frequently asked questions
Should I use Edge Delivery or AEM Sites?
Per surface, not per company. Marketing pages, blogs and campaign sites — where speed and publishing velocity dominate — fit EDS. Multi-locale governed estates, portals and workflow-heavy content fit Sites. Most enterprises run both deliberately.
Is EDS faster than AEM Sites?
Structurally, yes for delivered page performance: pre-rendered pages from edge nodes with phased JavaScript routinely score 90–100 on Lighthouse. A well-built Sites implementation can be fast; EDS is fast by default.
Does EDS support workflows and permissions like Sites?
EDS governance is intentionally lighter — preview/publish with document-tool sharing controls, or Universal Editor flows. Estates needing multi-step approvals, granular ACLs and translation pipelines remain Sites territory.
Can EDS and AEM Sites share content?
They share the Adobe ecosystem (Assets, analytics, Target) and can link seamlessly; content models differ, so plan which system owns which content type rather than syncing everything both ways.
Is Edge Delivery cheaper to build than Sites?
Typically yes for the surfaces it suits: block development in plain web tech is faster than component development in the full AEM stack, and operational overhead is lower. That economy is a reason to move suitable surfaces, not to force unsuitable ones.