A practical guide to choosing between Custom Metadata and Custom Settings for Salesforce integrations — covering deployment, performance, security, and scalability considerations.
Managing configuration data for integrations is a common architecture decision in Salesforce projects. Two built-in options — Custom Metadata and Custom Settings — look similar at first glance but have different strengths depending on deployment, runtime performance, and governance needs. This guide breaks down the differences and gives clear guidance for when to use each.
What is Custom Metadata?
Custom Metadata Types are metadata-driven configuration objects that behave like schema-level definitions. Records in Custom Metadata are treated as metadata, which makes them deployable via change sets, metadata API, and packaging. They’re ideal for configuration that should move between environments and be version-controlled alongside code.
Key benefits
- Deployable with metadata: records move with packages and change sets.
- Strong access controls via object & field-level security.
- Great for dynamic configuration patterns that must be consistent across environments.
- Scales well — suitable for many records and complex rule sets.
What is Custom Settings?
Custom Settings are configuration records stored as data (not metadata) and are available in two flavors: list and hierarchy. They’re designed for org- or profile-level settings and are cached in memory for very fast read access at runtime.
Key benefits
- Fast runtime access due to in-memory caching — useful when settings are read frequently.
- Simple model for org-wide or profile-specific defaults using Hierarchy Custom Settings.
- Easy to update in the org UI for administrators.
Trade-offs and limitations
- Deployment: Custom Metadata records are deployable as metadata; Custom Settings require separate data migration steps.
- Performance: Custom Settings typically read faster (cached), but Custom Metadata performance is acceptable and improves with careful design.
- Size & scale: Custom Settings have stricter size limits than Custom Metadata; large rule sets favor Custom Metadata.
- Security: Custom Metadata integrates with platform metadata security; Custom Settings rely on data-level access controls.
How to choose — practical guidance
- If you need configuration records to travel with code, be versioned, or packaged — choose Custom Metadata.
- If the integration requires frequent, high-performance reads and values are small and org-specific — consider Custom Settings.
- For environment-specific overrides (per profile or user), Hierarchy Custom Settings can be handy but plan migration carefully.
- When security and governance (packageability, CI/CD) matter — Custom Metadata generally wins.
Best practices
- Prefer Custom Metadata for environment-agnostic configuration and CI/CD-friendly deployments.
- Use Custom Settings sparingly for ultra-frequent reads where caching gives a measurable benefit.
- Combine patterns: store defaults in Custom Metadata and use Custom Settings or Custom Labels for transient overrides when necessary.
- Document migration steps and include configuration records in your release process (scripts or data loader exports) when using Custom Settings.
Choosing the right configuration store reduces deployment friction, improves runtime reliability, and makes integrations easier to maintain. The decision balances deployment needs, performance characteristics, and governance requirements — think about how frequently values change, whether they should be packaged, and who needs to manage them.
Why this matters: For Salesforce admins, developers, and integration architects, picking Custom Metadata vs Custom Settings shapes how you build repeatable, testable, and secure integration solutions. Treat configuration as a first-class part of your release process to ensure predictable behavior across sandboxes and production.