EcommerceViews doesn’t sell any platform licence or store build. We do offer paid strategy and SEO advice, and our author is Marketing Director at OpenCart, which is mentioned in this guide. Read how we review platforms in our review process and affiliate disclosure.
The short answer
Most stores selling under £1m a year should stay on a monolithic platform such as Shopify, WooCommerce, BigCommerce or OpenCart. Headless starts to pay off when page speed or a custom front end drives sales and you have developers on staff or on retainer. Composable suits larger retailers replacing several systems at once, usually well above £10m a year.
| Option | Best for | Typical build cost |
|---|---|---|
| Monolithic | Most stores under £1m a year, and many far bigger | A few hundred dollars for a template store; $30,000 to $120,000 (£22,500 to £90,000) for an agency build |
| Headless | Stores with developers whose front end has outgrown the theme | $50,000 to $250,000+ (£37,500 to £187,500+) |
| Composable | Retailers replacing several core systems, usually £10m+ a year | $150,000 to $350,000+ (£112,500 to £262,500+) to build, plus licences from about $40,000 (£30,000) a year |
Pounds are converted at $1 = £0.75 (17 October 2026). Sources for each figure are listed in the cost section and at the end of this guide.
What monolithic, headless and composable mean
The three options differ in how many pieces your store is split into, and who keeps those pieces working together.
Monolithic
The storefront your customers see, the commerce engine behind it and the admin all come as one system. Shopify with a theme, standard WooCommerce, BigCommerce with a Stencil theme and OpenCart all work this way. You get one login, one bill and one company to call when checkout breaks.
Headless
The storefront is split off from the commerce engine and talks to it through an API. Products, orders and payments stay on the same platform, but developers build the front end in a framework such as React or Next.js. That buys full control over design and page speed, and it also means you now own a second piece of software that needs upkeep.
Composable
The whole store is built from separate services that each do one job, such as search, product data or checkout, joined through APIs. Each part can be swapped later without rebuilding the rest. The trade is more vendors, more contracts and a team whose job is keeping them in step.
What MACH means
MACH stands for microservices, API-first, cloud-native and headless. The MACH Alliance uses it to describe software built from small, swappable parts. In practice it’s the label vendors put on composable commerce.
Where your store runs is a separate choice from how it’s built. Our guide to SaaS, PaaS and IaaS hosting for ecommerce covers that side.
What each costs to build and run
Headless usually costs two to three times as much to build as an agency-built monolithic store, and composable costs more again before you pay a single licence. The bigger difference is the monthly bill for the people who keep it running.
| Monolithic | Headless | Composable | |
|---|---|---|---|
| Build cost | $30,000 to $120,000 (£22,500 to £90,000) for an agency build; a template store can cost a few hundred dollars | $50,000 to $250,000+ (£37,500 to £187,500+) | $150,000 to $350,000+ (£112,500 to £262,500+) for a store doing $1m to $10m a year |
| Software and hosting | The platform plan, plus apps; hosting is included on hosted plans | The platform plan, plus front-end hosting of about $100 to $1,000 a month and an API layer of $100 to $500 a month | Licences from about $40,000 to $300,000+ a year for the commerce engine alone, plus each other service |
| Time to launch | 4 to 12 weeks | 8 to 20 weeks | 3 to 6 months for a simple direct-to-consumer store; 9 months or more with B2B and ERP links |
| People to keep it running | 25 to 65 hours a month of admin and vendor management | 90 to 340+ hours a month across front end, back end and DevOps | 3 to 5 developers for a store doing $1m to $10m a year |
The monolithic and headless figures come from our headless vs traditional platforms guide, with headless build quotes checked against Fudge. Composable figures are estimates from Swell and Elogic, because commercetools and most composable vendors don’t publish prices. Both companies sell competing or partner services, so treat their numbers as a starting range, not a quote.
Some headless costs have dropped. Shopify now includes Oxygen hosting for Hydrogen storefronts at no extra charge on paid plans, and a BigCommerce Catalyst store can run on Vercel’s Pro plan from $20 a month per developer seat before usage. The build and the developers are still the main cost.
Over three years the gap widens. Elogic’s mid-market estimate puts total cost at $375,000 to $865,000 for a monolithic store, $690,000 to $1.44m for headless and $1.32m to $2.93m for composable. Our total cost of ownership guide shows how to work out the same sum for your own store.
Which one fits your store
Start monolithic and move only when a specific problem forces you to. Three questions decide it: do you have developers, is the theme blocking a sales goal, and are you replacing several core systems at once?
Selling under £1m a year
Stay monolithic. A $50,000 headless build is a large slice of a year’s sales at this size, and the 90+ developer hours a month to run it cost more than most of these stores spend on their whole site. If pages are slow, compress images, remove unused apps and try a lighter theme first.
Selling £1m to £10m a year
Monolithic is still the default, but headless is worth pricing up if the front end is holding back sales and you already pay developers. Typical cases are running a web store and a mobile app from one back end, or a product builder that a theme can’t handle. Composable rarely fits here, since licences and the build together usually pass $200,000 in the first year.
Selling over £10m a year
Headless is common at this size. Composable becomes a real option when you’re replacing search, product data or order management at the same time and have at least five engineers working on commerce, which is the readiness line Elogic suggests. Plenty of retailers this size still run happily on Shopify Plus or Adobe Commerce without going headless.
Headless on the platform you already use
You don’t have to change platform to go headless. Shopify and BigCommerce both offer their own front-end frameworks, while WooCommerce and OpenCart rely on community or third-party tools.
Shopify: Hydrogen and Oxygen
Hydrogen is Shopify’s React framework for custom storefronts, and Oxygen is the hosting it deploys to. Oxygen comes at no extra charge on paid Shopify plans, from Basic upward, according to Shopify’s developer docs. A full Hydrogen build usually takes one to three React developers three to six months, with agency quotes of $50,000 to $250,000+ reported by Fudge. Many theme apps won’t work on a Hydrogen front end, so check yours before you plan. Read our Shopify review for the platform itself.
BigCommerce: Catalyst
Catalyst is BigCommerce’s open-source storefront, built on Next.js and its GraphQL Storefront API. It comes with a working store out of the box, so developers start from a finished checkout instead of a blank page. It also supports Makeswift, a visual editor that lets marketers change pages without a developer. You choose your own hosting, such as Vercel. See our BigCommerce guide.
WooCommerce
WooCommerce has no official headless framework. The usual route is the WPGraphQL plugin with its WooCommerce extension to expose store data, and a separate front end, often Next.js. You end up maintaining WordPress, the plugins and the front end, so it suits teams that already know WordPress well. See our WooCommerce review.
OpenCart
Disclosure: our author is Marketing Director at OpenCart. OpenCart’s built-in API covers carts and orders, so headless OpenCart builds usually add a REST API extension or use an agency such as Webkul to connect a React or Next.js front end. Most OpenCart stores get better value from a lighter theme and caching than from a headless rebuild. See our OpenCart review.
Moving between architectures
The safest move is the smallest one. Going headless on your current platform keeps your products, customers and orders where they are, and only the front end changes.
A few things decide whether the move goes smoothly:
- Your URLs. A new front end often changes page addresses, and every old one needs a 301 redirect. Our replatforming SEO checklist covers this step by step.
- Your apps. Reviews, upsells and tracking scripts built for a theme often stop working on a custom front end. List them and check each one has an API version before you start.
- Who edits pages. Once the theme is gone, marketing may need a developer for every banner unless you add a visual editor or a headless CMS.
- Your hosting. If the back end is moving too, our cloud migration guide covers moving servers without downtime.
Composable can be done in stages, swapping one part at a time instead of rebuilding everything at once. Elogic estimates that staged approach at 18 to 30 months, against 9 to 18 months for a full rebuild.
FAQs
What is the difference between monolithic, headless and composable ecommerce?
A monolithic platform runs the storefront and the commerce engine as one system. Headless splits off the storefront so developers can build it separately. Composable goes further and builds the whole store from separate services, such as search, checkout and product data, joined through APIs.
Is headless commerce worth it for a small store?
Usually not. A headless build starts around $50,000 and needs 90 or more developer hours a month to run. For a store selling under £1m a year, a faster theme and fewer apps nearly always give a better return.
How much does headless or composable ecommerce cost?
Headless builds typically cost $50,000 to $250,000+, plus front-end hosting and developer time. Composable builds for a store doing $1m to $10m a year are estimated at $150,000 to $350,000+, plus licences from about $40,000 a year.
What is MACH architecture?
MACH stands for microservices, API-first, cloud-native and headless. It describes commerce software built from small, swappable parts that connect through APIs, and it’s the standard behind most composable platforms.
When should I move off Shopify or WooCommerce to headless?
When a specific sales goal needs something the theme can’t do, and you have developers to build and maintain it. Examples are running a web store and an app from one back end, or a product builder a theme can’t support. Speed alone is rarely the reason, since most slow stores can be fixed without a rebuild.
How do I migrate without losing rankings?
Map every old URL to its new one and set up 301 redirects before launch. Keep titles, descriptions and structured data, then watch Search Console for errors in the first weeks. Our replatforming SEO checklist walks through each step.
How we researched this guide
We checked every cost and platform detail against the sources below in October 2026. Composable vendors such as commercetools don’t publish prices, so those figures are estimates from companies that sell related services, and we say so where they appear. Pounds are converted at $1 = £0.75.
- EcommerceViews: Headless commerce vs traditional platforms (monolithic and headless build costs, running costs, hours)
- Fudge: Headless Shopify with Hydrogen (Hydrogen build quotes, team size, timeline)
- Shopify: Hydrogen and Oxygen fundamentals (Oxygen plans and cost)
- BigCommerce: What is Catalyst
- Vercel pricing (Pro plan)
- WPGraphQL for WooCommerce
- Webkul: OpenCart headless development
- Swell: commercetools pricing (licence and implementation estimates)
- Elogic: commercetools pricing (licence estimates)
- Elogic: Composable vs headless vs monolith (definitions, three-year cost, team readiness)
- MACH Alliance