As Shopify stores scale, one question comes up again and again during client discovery calls:
“Should we use a public Shopify app, or build a custom one?”
For Shopify agencies and developers, this isn’t just a technical decision—it’s a strategic one that impacts performance, cost, security, scalability, and long-term client satisfaction.
This guide breaks down custom vs public Shopify apps, explains when each makes sense, and helps agencies confidently advise clients based on real-world business needs—not guesswork.
What Is a Public Shopify App?
A public Shopify app is a pre-built application listed on the Shopify App Store, designed to serve a wide range of merchants with common use cases.
Common Examples
- Email marketing tools (Klaviyo, Omnisend)
- Reviews and UGC apps
- Upsells and bundles
- Subscription management
- Loyalty and rewards programs
Public apps are typically:
- Built for mass adoption
- Subscription-based
- Easy to install and configure
- Maintained and updated by third-party vendors
What Is a Custom Shopify App?
A custom Shopify app is built specifically for a single store (or group of stores) to solve unique business requirements that public apps can’t fully address.
Custom apps can:
- Integrate Shopify with ERPs, CRMs, WMS, or PIMs
- Automate complex workflows
- Enforce custom pricing, permissions, or logic
- Support proprietary business processes
- Improve performance by eliminating unnecessary features
These apps are typically:
- Built by an agency or in-house development team
- Owned entirely by the merchant
- Hosted externally (or via Shopify infrastructure)
- Tailored to the client’s exact needs
Key Differences: Custom Apps vs Public Apps
1. Flexibility & Customization
Public Apps
- Limited to features provided by the vendor
- Customization is often constrained
- Requests for changes may not align with the vendor’s roadmap
Custom Apps
- Built around the client’s workflows
- Fully customizable logic and UI
- Can evolve alongside the business
Agency Insight:
If a client repeatedly says “We almost need this to work slightly differently”, that’s usually a sign a custom app is the better fit.
2. Performance & Store Speed
Public Apps
- Often load scripts across many stores
- Can add unused features and bloat
- Multiple apps can significantly impact performance
Custom Apps
- Built lean with only required functionality
- No unnecessary scripts or assets
- Optimized for the store’s specific traffic patterns
Agency Insight:
For high-traffic Shopify Plus stores, custom apps often outperform stacked public apps—especially when performance directly affects conversion rates.
3. Cost Considerations
Public Apps
- Monthly subscription fees
- Costs increase as store scales
- Long-term expenses can exceed custom build costs
Custom Apps
- Higher upfront development cost
- Lower (or no) recurring fees
- Ongoing maintenance controlled by the merchant
Agency Insight:
For clients paying $300–$1,000/month across multiple apps, a one-time custom solution often becomes cheaper within 12–18 months.
4. Security & Data Control
Public Apps
- Data handled by third-party vendors
- Security depends on external compliance
- App permissions may exceed what’s actually needed
Custom Apps
- Full control over data access and storage
- Permissions limited to exact requirements
- Easier to meet enterprise or compliance standards
Agency Insight:
For B2B, wholesale, healthcare-adjacent, or regulated industries, custom apps offer far greater peace of mind.
5. Scalability & Long-Term Growth
Public Apps
- Built for generic use cases
- May struggle with edge cases at scale
- Vendor limitations can stall growth
Custom Apps
- Designed with future growth in mind
- Can scale alongside order volume and complexity
- Easier to extend with new features
Agency Insight:
If a client plans rapid expansion, international markets, or complex backend integrations, custom apps prevent future replatforming headaches.
When Public Apps Are the Right Choice
Public apps are ideal when:
- The client needs a standard feature quickly
- Budget is limited
- The store is early-stage or validating a concept
- The app has a strong reputation and support team
- Performance impact is minimal
Example:
Using Klaviyo for email marketing instead of building a custom email system makes perfect sense.
When Custom Apps Are the Better Solution
Custom apps are often the best choice when:
- The client has unique business logic
- Multiple apps are being used to patch one workflow
- Performance issues are affecting revenue
- Deep integrations with external systems are required
- The business is scaling rapidly
- The client wants full ownership of their tech stack
Example:
A Shopify Plus merchant needing custom pricing rules tied to an ERP and customer tags will almost always require a custom app.
A Hybrid Approach: Best of Both Worlds
Many successful Shopify builds use a hybrid approach:
- Public apps for standardized functions
- Custom apps for proprietary workflows
This allows agencies to:
- Reduce development time
- Control costs
- Maintain flexibility where it matters most
Agency Best Practice:
Audit existing apps regularly and replace high-cost, low-value subscriptions with custom solutions when ROI makes sense.
How Agencies Should Guide Clients
As a Shopify agency or developer, your role isn’t just implementation—it’s advisory.
Ask clients:
- What processes are currently manual?
- Which apps feel limiting or bloated?
- Where are monthly app costs adding up?
- What integrations are business-critical?
- What does success look like in 12–24 months?
Then recommend:
- Public apps for speed and simplicity
- Custom apps for control, performance, and scalability
Final Thoughts
There’s no one-size-fits-all answer in the custom vs public Shopify app debate.
The right solution depends on:
- Business complexity
- Growth trajectory
- Performance expectations
- Budget strategy
- Long-term ownership goals
For Shopify agencies and developers, understanding these trade-offs allows you to build smarter, more scalable solutions—and position yourself as a true strategic partner, not just a service provider.
