Custom Shopify App or App Store App? How to Decide

Most Shopify stores should not build a custom app. An App Store app is cheaper to start, gets updated by someone else and can be removed in a minute. A custom app makes sense in a narrower set of cases: your process is genuinely unusual, you are paying several apps to do one job badly, or your data has to move between Shopify and a system no public app supports. This guide gives you the questions we use to decide, before anyone writes code.

Every platform detail below was checked on 5 November 2026 against Shopify's Help Centre and developer documentation, which we link as we go.

What is the difference between a custom app and a public app?

A public app is built once and sold to many stores through the Shopify App Store. It goes through Shopify's app review, it bills you through your Shopify invoice in most cases, and its developer carries the cost of keeping it working as Shopify changes.

A custom app is built for your store only. Shopify's Help Centre describes it as "an app that you or a developer builds exclusively for your Shopify store, unlike a public app that's built for many stores to use." It can add features to your admin, read and write your store data through Shopify's APIs, or push your catalogue to other platforms through the Storefront API.

Two platform facts change how this decision looks in late 2026:

• New custom apps are built in the Dev Dashboard. Shopify's help page on apps says custom apps are now created and managed in the Dev Dashboard. Legacy custom apps created in the Shopify admin before 1 January 2026 can still be managed there, but that route is closed for new apps.
• Custom distribution can cover more than one store. According to Shopify's app distribution documentation, a custom-distribution app can be installed on a single store, on multiple stores that belong to the same Plus organisation, or on development stores. It cannot charge through Shopify's app billing system, which matters only if you planned to resell it.

The distribution choice is also permanent. Shopify's documentation says you cannot change the distribution method after you select it, so an app built as custom cannot later be listed on the App Store without starting a new app.

When is an App Store app the right answer?

Start with the App Store whenever the job is common. Reviews, subscriptions, loyalty, product bundles, search, size charts, wishlists and shipping rate tables are problems thousands of stores share. The best apps in those categories have had years of bug reports from other merchants. You would be paying to rediscover those bugs.

A public app is usually right when all of these are true:

1. The workflow is standard. If you can describe what you need in one sentence that another merchant would recognise, an app probably exists.
2. Configuration covers 80 percent of it. It is common for a merchant asking for a custom build to have never explored the settings page of the app they already pay for. Read the settings, then the app's help docs, then ask the developer. Many "missing features" are a toggle.
3. The app is maintained. Check the date of the last listing update and recent reviews, and look for the Built for Shopify badge. Shopify says apps with that badge "cannot decrease your storefront's speed by more than 10 performance points," and the status is reviewed every year.
4. You can live with its data model. Some apps store data in their own database rather than in Shopify metafields. If you leave, that data may not come with you. Ask before you install.

The hidden cost of public apps is not the monthly fee. It is the pile-up. Five apps that each inject scripts into your theme can slow product pages more than one well-built feature would. We wrote about how that happens, and how to cut it back, in our Shopify app stack audit.

When does a custom app actually pay off?

A custom app earns its keep in four situations that come up often with Indian D2C and B2B brands.

1. You are stitching three apps together to do one job

A common example is wholesale: one app for price lists, another for order minimums, a third for a quick-order form, plus a Flow workflow to tag customers. Each app works. Together they fight. A single custom app, or a few Shopify Functions, often replaces the stack with less code running on the storefront.

2. Your data lives in a system no public app supports

Tally, a regional ERP, a warehouse system built by a local vendor, a dealer portal. Public connectors exist for the big names, but if your inventory and invoices sit in a system used by a small number of businesses, nobody will build an App Store app for it. A custom app that syncs orders, stock and prices is often the only clean route.

3. The feature is your edge

If the thing you are building is the reason customers pick you, a product configurator for made-to-measure clothing or a jewellery price that updates with the day's gold rate, renting it from an app developer who sells the same feature to your competitors is a strategic risk.

4. Privacy or compliance rules out a third party

Some businesses cannot send customer data to an outside vendor's servers. A custom app keeps the data path between Shopify and systems you control. Note that Shopify ties some customer data access to plan level: its help page says that to access Custom Level 2 PII apps, a store must be on the Grow plan or higher.

What does a custom app cost to own after launch?

The build is the visible cost. Ownership is the one that catches merchants out, because Shopify's APIs keep moving.

Shopify's Help Centre says new API versions are released every three months, and each version keeps working for a year before developers must move to a newer one. If a change breaks an app, Shopify notifies the developer, who then has nine months to update it. After that, the app "becomes unsupported and might stop working as expected."

For a public app, that upgrade work is the developer's problem, spread across all their customers. For a custom app, it is yours. Budget for it in three ways:

• An owner. Someone, in-house or an agency on retainer, must read Shopify's developer changelog and act on deprecation emails. Shopify sends unsupported-app warnings to the staff or collaborator account associated with the app, so make sure that account belongs to someone who still works with you.
• Hosting and monitoring. Most custom apps run on a server you pay for. Logs, error alerts and a way to replay failed webhooks are not optional if the app moves orders or stock. Our post on monitoring custom app integrations covers what to watch.
• Access to the code. Insist on the repository living in an account you own. If the developer disappears, Shopify's own advice is to hire a Shopify Partner to make the required changes, and that partner needs the code.

For build budgets, we broke down what drives the price in our guide to custom app development cost in India. We will not repeat the ranges here, because scope moves them more than anything else.

How do you decide between custom and public, step by step?

This is the order we work through with merchants. It takes an hour if you are honest with the answers.

1. Write the job in one paragraph. What triggers it, what data it touches, who sees the result. If you cannot write it, you are not ready to build anything.
2. Search the App Store with three different phrasings. Merchants and app developers name things differently. "Gold rate pricing", "dynamic pricing" and "metal price update" bring up different apps.
3. Trial the top two apps on a development or staging copy. Test with your real catalogue, not demo products. Variant counts and metafields break more apps than anything else.
4. List the gaps. If the gaps are cosmetic, a small theme change usually closes them. If they are about data or logic, keep going.
5. Check whether Shopify already solves it natively. Shopify Flow, Functions for discounts and checkout validation, metaobjects and the built-in B2B features have absorbed many jobs that used to need an app.
6. Price the custom route over three years, not the first month. Build, hosting, API upgrades every year and someone to answer the phone when it breaks. Then compare with three years of app fees.
7. Decide who owns it. If nobody will own the app after launch, do not build it.

Can you start with an app and move to custom later?

Yes, and it is often the smartest path. Run the public app for six months, learn what your team actually uses, then build a custom version that does only that. You will write a far better specification after living with the problem.

Two things make the later move painless:

• Keep your data in Shopify where you can. Prefer apps that store their configuration and results in metafields or metaobjects. A custom app can then read the same data without a migration project.
• Export regularly. If the app holds data outside Shopify, such as reviews, loyalty points or subscription contracts, check the export format before you depend on it.

The reverse move also happens. It is also common to find a custom app built years ago that now duplicates a feature Shopify ships natively. Retiring that app removes a maintenance bill and a failure point.

What should a custom app brief include?

If you do decide to build, a clear brief cuts the quote and the timeline. Include these items and any good developer can estimate it properly:

• The one-paragraph job description from step 1 above.
• Every system it connects to, with API documentation or the vendor's contact.
• Expected volume: orders a day, SKUs, peak days such as Diwali or a sale.
• Who uses it inside the admin, and on which device.
• What happens when it fails. Should orders still go through? Who gets alerted?
• Who will own the code, the hosting account and the Dev Dashboard access.

A developer who does not ask about failure handling and ownership is quoting for the happy path only.

So which should you choose?

Default to the App Store. Move to custom when the job is unusual, when several apps are fighting to do one thing, when your data sits in a system nobody else supports, or when the feature is your competitive edge. Then budget for owning it, not just building it.

Not sure which side your problem falls on? Write to us at hello@exactwhy.com with the subject "Custom app or public app review" and a short description of the job. We will look at your current app stack and the problem for free, and tell you honestly whether an existing app, a native Shopify feature or a custom build fits. If a build makes sense, we quote it after that review, and ongoing app maintenance is available on a monthly retainer.