Webhook vs API: Key Differences, Use Cases & How to Choose

Webhooks and APIs serve the purpose of allowing software systems to share information, yet they approach communication initiation differently.

An API typically waits for a request from another application to provide data or execute an action. In contrast, a webhook sends an automated notification to a specified URL when a predefined event takes place.

For businesses, particularly revenue-focused teams, employing both of these technologies together can streamline lead processing. A form submission, for instance, can initiate a workflow, while an API enriches the lead with comprehensive company and contact details before scoring or routing. This contextual enrichment surpasses what a simple form submission can offer.

The fundamental distinction between a webhook and an API lies in their method of communication: request-response versus event-driven. APIs remain in a state of pause until a system sends a request. Conversely, webhooks are pre-configured to dispatch an HTTP request whenever a particular event materializes.

An API, or application programming interface, outlines how one software system can solicit data or functionality from another. It generally employs a request-response pattern: an application sends a request to an endpoint, and the recipient returns data, performs an action, or reports an error. Use an API when your application needs specific information or wishes another system to execute an operation.

Common applications include retrieving customer data, creating or modifying CRM records, checking order status, enriching leads, processing transactions, and conducting searches.

For example, when a sales representative opens a company page, an API request is triggered to retrieve current company information. An API response delivers the requested data to the application for display.

On the other hand, a webhook is an event-driven HTTP callback that transmits data to a designated URL upon the occurrence of a specified event. Rather than incessantly checking for changes, the receiving application anticipates the source system to notify it of any relevant event.

Webhooks are utilized when the source system signals an event, requiring another application to respond. Common triggers encompass form submissions, payment status modifications, email bounce-backs, subscription terminations, support requests, shipping updates, and the completion of background processes.

An example of webhook implementation is when a prospect submits a demo form. The form platform immediately forwards the record to a webhook endpoint, initiating a lead qualification workflow.

Both webhook and API integration are beneficial when an event necessitates a workflow that depends on supplementary data or actions. Typically, the pattern involves a webhook trigger initiating a workflow, followed by an API call to retrieve data, application of business rules, and another API call to update another system.

In a lead request scenario, a webhook could be triggered, which in turn initiates a workflow that calls an enrichment API for account and contact information. After qualification and routing rules evaluate the enriched record, another API call updates the CRM and assigns the lead. This hybrid approach combines the event-driven notification of webhooks with the extensive data access and actions provided by APIs.

For more intricate revenue workflows, consult resources on building a RevOps tech stack to understand systems of record, integration ownership, and data flow. The decision between using an API or webhook becomes clearer when comparing how each system initiates communication, manages data, and supports workflows.

An API is initiated by the application requiring data or an action. Conversely, a webhook is initiated by the system where the event occurred. For instance, an application might call an API to check an order's status, while a shipping platform transmits a webhook upon the order's delivery. APIs typically adhere to a request-response model: the client makes a call, and the server responds.

Webhooks, being event-driven, transmit information upon the occurrence of a defined event without awaiting the receiving system's request.

API requests generate immediate success or error responses. Webhooks, however, necessitate consideration for failed or delayed deliveries, retries, duplicate events, time-outs, and missing acknowledgments due to their variable delivery behavior. API security commonly involves API keys, access tokens, OAuth, and permissions, whereas webhooks require a secured endpoint, usually HTTPS, signed or secret verification, payload validation, and safeguards against replay attacks.

Both systems demand clear accountability in a production environment. Lead routing exemplifies why these two technologies are generally complementary rather than competing choices. Our lead tracking guide addresses the software aspect of maintaining ownership, follow-up, activity, and pipeline visibility after the record reaches sales, while our lead scoring guide covers how sales and marketing teams can amalgamate fit, engagement, predictive models, and buying signals to determine which prospects merit attention.

ZoomInfo's Enrich API can augment partial lead records with company, contact, firmographic, technographic, hierarchy, and buyer data before scoring and routing. A typical workflow is form submission, followed by a webhook, the ZoomInfo Enrich API, lead scoring, routing rules, and finally, CRM assignment. Here, the webhook initiates the workflow, while ZoomInfo's API supplies the B2B context necessary for evaluation.