Salesforce offers powerful automation tools to streamline business processes. Two of the most common are Salesforce Flow (declarative, point-and-click automation) and Apex Triggers (custom code). Both can run when records are created or updated, but they differ in capability and use cases.

In this post we’ll explain what each tool is. We will compare their pros and cons. Finally, we’ll highlight when to use one over the other. We’ll also include an example Flow diagram and sample Apex Trigger code. Whether you’re an admin or a budding developer, this guide will help you pick the right tool for each scenario.

What Is Salesforce Flow?

Salesforce Flow is a declarative automation tool that lets you build processes with a visual interface – no code required.

Flows can run on various events. Record-triggered flows fire before or after a record is saved. Scheduled flows run on a schedule. Screen flows guide users through input forms. Because Flows use drag-and-drop elements (like Get Records, Update Records, Decisions, Loops, etc.), even non-developers can build them. For example, a Flow could automatically set a field value when a record is created. It could also send an email when conditions are met. Additionally, it can loop through related records to update them.

Flows are ideal for “clicks not code” automation. They integrate easily with Salesforce objects and data (using pre-built elements) and include built-in debugging tools. Flows run on the platform. They honor the same governor limits as Apex. However, they offer the convenience of point-and-click setup. Salesforce even provides Fast Field Update (before-save) Flows. These run before the record is committed. They are extremely efficient for simple field updates. They are often cited as ~10× faster than after-save flows.

You can refer to our previous blog for more detail understanding on flow – Learning Salesforce Flows – Part 1 – Difference between workflow, process builder and flows & Learning Salesforce Flows – Part 3 – Understanding the Types of Salesforce Flows and Best Practices

What Is an Apex Trigger?

An Apex Trigger is custom Salesforce code. It runs before or after database operations (like insert, update, delete) on a record.

Triggers are written in Salesforce’s Apex language. They can contain any logic you need. This ranges from querying and updating records to calling external services. For example, a trigger could enforce complex business rules. It might update multiple related objects in one transaction. It could also call a web service. Because it’s code, Apex provides complete freedom for business logic, data transformations, and integrations. Apex Triggers excel when “performance and scale is important” or when the logic is too complex for point-and-click tools.

In practical terms, use a Trigger when your automation requirements exceed what Flows can do easily. This might include handling very large data volumes. It could also involve intricate multi-step calculations. Some integration’s require asynchronous Apex, like future or batch jobs. Triggers require development skills (and unit tests), but they give you power and control that Flows cannot match.

You can refer to our previous blog for more detail understanding on trigger- Learning Apex Triggers (Part 1) – Understanding Trigger Basics & Learning Apex Triggers (Part 3) – Comprehensive Guide to Before and After Trigger Scenarios

Pros and Cons of Flows vs. Triggers

Both Flows and Triggers have strengths and trade-offs. Here’s a quick comparison to help you decide:

📊 Comparative Overview

Aspect	Salesforce Flow (Pros)	Salesforce Flow (Cons)	Apex Triggers (Pros)	Apex Triggers (Cons)
Ease of Use	Drag-and-drop builder. Easy for admins to learn and maintain.	Requires understanding of logic, variables, and formulas. Has a learning curve despite being “no-code.”	Full control and flexibility to write any logic, including complex calculations and custom transformations.	Requires coding knowledge, creating dependency on developers and technical knowledge.
Development & Deployment Speed	Low-code approach enables quick deployment and faster response to changes. No code coverage requirement – flows deploy without test classes.	Limited to built-in actions, can’t execute arbitrary code or sophisticated algorithms.	Offers robust unit testing framework to catch errors before deployment.	Deployment involves change sets or metadata/API. Requires test classes to be created with coverage (≥75%) making it more time-consuming.
Integration	Works seamlessly with Salesforce objects, formulas, and security. Can also do HTTP Call out to OpenAPI 2.0 JSON supported api’s	Tied to Salesforce, complex integrations or external API calls need Apex.	Supports external integrations (REST/SOAP API calls) without requiring Flow or additional steps.	Maintenance and updates can be more resource-intensive.
Complexity	Pre-built actions allow rapid assembly of simple automation.	Hard to manage for very complex logic or large-scale processes.	Handles complex, multi-step algorithms and custom transformations efficiently.	Higher risk of errors if not written or maintained properly.
Performance	Efficient field updates with “before-save” record-triggered Flows.	Limited performance on large data sets. Can hit governor limits or timeout.	High performance on bulk data processing with bulkification and asynchronous options.	Poorly written triggers can cause governor limit issues or unintended data changes.
Large Data Volumes (LDV)	Handles small to medium record sets efficiently.	May encounter issues with handling large data volumes or complex processing.	Designed for high performance on large datasets in a single transaction.	N/A
Complex Queries	Limited in handling complex SOQL queries directly within the Flow.	May require workarounds or Invocable Apex for complicated logic.	Easily manages advanced SOQL queries and complex business logic.	Can become challenging to maintain with overly complex logic.
Governor Limits	Efficient for simple field updates using before-save flows.	Max 2,000 elements per flow interview till API version 56.0 and earlier. Max number of versions 50 and other limits. Governor limits still applies.	Optimized for handling large datasets when using techniques like Batch Apex.	Governor limits (100 total SOQL/ 50000 number of records retrieved / 150 – DML, CPU time, heap size) apply and can lead to issues
Error Handling	Fault connectors handle basic errors. Debugging is visual but limited in granularity for complex flows.	Errors roll back the entire transaction if uncaught. Debugging large flows is cumbersome.	Supports try/catch for detailed error handling, with extensive logging and debugging tools available	Requires manual implementation of exception handling, which increases development effort.
Asynchronous Options	Natively lacks many options for asynchronous operations.	N/A	Supports @future methods, batch Apex, and schedulable classes for deferred or long-running tasks.	N/A
Testing Tools	Flow Builder includes debuggers and test modes to step through logic.	N/A	Robust unit testing and code coverage ensure stability and compliance.	Need to write test classes for testing. Writing and maintaining test classes increases development effort.

In summary, Flows are easier and faster for straightforward automations. Triggers are more powerful and scalable for complex or performance-critical tasks. The right choice often depends on the scenario.

When to Use Flows

Flows are an excellent first choice for many common automation needs, especially if you want to avoid code:

• Simple record updates or calculations. If a requirement is as straightforward as concatenating two fields(e.g. FirstName + LastName) , a Before-Save Flow can do it in seconds. It can also set a default value quickly. Additionally, it copies a field from one record to another in seconds.
• Related record changes via GUI. Need to update child or parent records when a record changes? An After-Save Flow can query related records and update them. For instance, when an Opportunity closes, you might use a Flow to update a related Customer’s status. You could also roll-up a value to the parent Account. Screen Flows (with screens) can also walk users through guided data entry.
• Email alerts and notifications. Flows can send email or Chatter posts in response to events (actions that after-save Flows support). If a case priority goes to “Critical,” a Flow can trigger an email to the service team without code.
• Guided user interactions. Screen Flows (Lightning Flows) are great for building multi-step wizards and form-filling experiences for users. Apex triggers have no concept of user screens.
• Scheduled batch updates. Auto-launched Flows can be scheduled (e.g. nightly) to perform routine tasks like sending weekly reports or updating records en masse. This can cover many admin tasks that used to be done with time-based Workflow or custom Apex schedulers.
• When admins need flexibility. If you expect requirements to change frequently, Flows are preferable. They empower admins to tweak the logic without a developer. Flows are easier to modify. In short, Flows suit lighter-weight, frequently-changed automations.

Tip: Use a Before-Save Flow when you only need to update fields on the record that triggered the flow (e.g. auto-filling fields). These run very efficiently (no extra DML). Use an After-Save Flow when you need to work with other records (create or update related records, send emails, etc.)

When to Use Apex Triggers

While Flows cover a lot of ground, there are scenarios where Apex Triggers (and other Apex code) are the better choice:

• Complex business logic. If your requirements involve intricate formulas, you should use code. Advanced branching or algorithms, such as iterative calculations, custom matching logic, or nested loops, are handled more cleanly with code. For example, syncing thousands of related records with error-handling requires Apex. You might need batch jobs. This is preferable to a monolithic Flow.
• Large data volumes. When processing bulk data (think hundreds or thousands of records at once), Apex can be optimized for performance. Triggers in Apex can leverage batch or Queueable Apex to handle millions of records efficiently. Flows, by contrast, will hit governor limits or slow down if given too many records.
• External system integrations. If you need to call external web services or perform callouts in response to data changes, Apex is required. Triggers (and Apex classes) support HTTP callouts, whereas Flows require an Apex invocable or other workarounds for callouts. Similarly, for complex integrations (REST/SOAP, message queues, etc.), Apex gives you the needed flexibility.
• Transaction control. Apex allows more fine-grained control of transactions. You can use database methods to roll back partially, or use limits to ensure bulkification. If you need sophisticated error logging, like writing error records on failure, Apex is the way to go. It is also suitable for partial rollback.
• Performance-critical needs. For CPU-intensive or high-throughput tasks, well-written Apex triggers can outperform equivalent Flows. For example, doing intensive computations or processing in a loop is usually faster in compiled Apex code.
• Triggers must be used when Flow can’t: There are some actions Flows simply can’t do by themselves (no Delete Records in a before-save Flow, no Apex callout, etc.), so use Apex when you hit those limits. Some editions only support certain features. For example, Enterprise and above can use Apex. However, Professional Edition doesn’t allow custom code.

In short, use Apex Triggers for “heavy lifting”: tasks that require performance, scale, or capabilities beyond the built-in declarative features.

Best Practices for Choosing Between Flows and Triggers

Here are some guidelines to help you decide which tool to use, based on complexity, maintainability, performance, and scalability:

1. Start with clicks: Always consider a Flow first for any new automation. If you can solve the requirement with a declarative solution, it’s often faster and simpler. Many admins can build and change Flows without developer involvement.
2. Assess complexity: If the logic becomes very complex or needs custom processing (e.g. complex loops, calculations, or integrations), that’s a signal to move to Apex Trigger. Flows have limits on what actions they can perform; use Apex if you need more.
3. Consider volume and performance: Flows run with the same governor limits as triggers. However, for large data volumes, Apex can provide optimizations. These include bulk processing and asynchronous batch jobs. If you expect to process hundreds or thousands of records in one go, Apex is likely a better long-term solution.
4. Error handling: Apex gives finer control for errors (catch exceptions, log to custom objects, partial rollbacks). Flows have basic fault paths and email alerts, but complex error management is easier in code.
5. Execution timing: Use a before-save flow (fast update) when you only need to change the triggering record’s fields. Use an after-save flow when you need to create or update other records. Apex triggers have similar before/after timing. Note that before-save flows actually run before Apex before-triggers. Small updates can be handled by flows even before your Apex code executes.
6. Scalability: For very large scaling needs (millions of records), consider Batch Apex or Queueable Apex. Flows have scheduled paths (for delayed actions). They have configurable batch sizes in record-triggered flows. However, they are not as mature as Apex batch jobs.
7. Testing: Apex requires unit tests with 75% code coverage to deploy. Flows have debug tools but no formal test framework. If your organization values formal testing, Apex triggers fit that model; if you prefer low-maintenance, Flows reduce the testing overhead.
8. Skill and resources: If you lack developer resources, lean on Flows for as much as possible. If you have Apex devs on hand and the needs justify it, use triggers or Apex classes.

In general, a good rule of thumb is: Use Flow for simple or frequently changing processes. Use Apex Trigger or Apex code for complex, heavy-duty, or performance-critical processes. By matching the tool to the task, you can build robust, maintainable automations in Salesforce.

Record Automation Tools Suggestion

You can also refer this Salesforce Architect article for recommendations for various triggered automation on a record.

📊 Comparative Overview

Use Case	Before-Save Flow	After-Save Flow	After-Save Flow + Apex	Apex Trigger
Same-Record Field Updates	✅ Available	⚠️ Not Ideal	⚠️ Not Ideal	✅ Available
High-Performance Batch Processing	⚠️ Not Ideal	⚠️ Not Ideal	⚠️ Not Ideal	✅ Available
Cross-Object CRUD Operations	❌ Not Available	✅ Available	✅ Available	✅ Available
Asynchronous Processing	❌ Not Available	✅ Available	✅ Available	✅ Available
Complex List Processing	❌ Not Available	⚠️ Not Ideal	✅ Available	✅ Available
Custom Validation Errors	✅ Available	✅ Available	❌ Not Available	✅ Available

Legend:

• ✅ Available: Suitable for the use case.
• ⚠️ Not Ideal: Possible but may have limitations.
• ❌ Not Available: Not supported.

Conclusion

Both Salesforce Flow and Apex Triggers are essential automation tools. Flows empower admins with a no-code builder. They are great for many common scenarios. Apex Triggers offer the ultimate control and power for advanced requirements. Understanding their differences, pros/cons, and best-fit scenarios will help you choose the right approach and build efficient automations.