Webhooks vs APIs: When to Use Each

Building an integration? Decide: poll an API for updates or set up webhooks to receive them automatically. This choice shapes infrastructure costs and user experience. If you're new to webhooks, see our complete guide on what webhooks are.

Push vs Pull: The Fundamental Difference

APIs: The Pull Model

With traditional REST APIs, your application asks for data when it needs it. Think of it like checking your mailbox—you walk out, look inside, and either find mail or don't. If you want to know the moment something arrives, you'd need to check constantly.

Your App External Service | | | GET /orders/latest | |------------------------------------>| | | | Response: { orders: [...] } | |<------------------------------------| | | | (5 minutes later) | | GET /orders/latest | |------------------------------------>| | |

Webhooks: The Push Model

Webhooks flip this around. Instead of asking for updates, you tell the external service where to send them. Now imagine a mail carrier who rings your doorbell the moment a letter arrives—no more checking an empty mailbox.

Your App External Service | | | Subscribe to order.created | |------------------------------------>| | | | (Event occurs) | | | | POST /your-webhook-endpoint | | { event: "order.created", ... } | |<------------------------------------| | |

Webhooks vs APIs: A Direct Comparison

When to Use APIs

On-demand data retrieval: When users request information (searching products, viewing order history), APIs are natural—you fetch specific data at a specific moment.

Bulk data operations: Syncing large datasets, batch processing, or generating reports work better with API calls where you can paginate and handle rate limits.

Low update frequency: If data changes once daily, polling every few hours is adequate. Webhook overhead isn't justified.

Need full control: APIs let you decide when to fetch data—essential when coordinating timing across systems or working within strict processing windows.

When to Use Webhooks

Payment Processing: Stripe, PayPal and others send webhooks instantly when charges succeed, fail, or subscriptions change. Delays here directly impact revenue and user experience.

Real-Time Notifications: Chat, collaboration tools, and social platforms need instant notifications. Webhooks avoid constant polling drains on batteries and bandwidth.

Inventory Updates: E-commerce platforms receive stock changes from suppliers via webhooks—preventing overselling and keeping availability accurate across channels.

CI/CD Pipelines: GitHub webhooks trigger builds and deployments when code is pushed. Polling commits would add unnecessary latency.

SaaS Integrations: CRM leads, support tickets, form submissions—webhooks let you react instantly, trigger automations, and sync systems in real-time.

When to Use Both

Speed + reliability: Use webhooks for real-time updates, fall back to API polling when webhooks fail to catch anything missed.

Minimal payloads: Webhooks notify you something happened, then you fetch complete records via API—reducing payload sizes and ensuring current data.

Initial sync + ongoing: Use APIs to pull historical data during onboarding, then switch to webhooks for future updates. Most CRM and data sync tools use this pattern.

Real-World Example: Subscription Billing

Building a SaaS product with Stripe subscriptions:

1. Webhooks for events: Stripe sends invoice.paid, customer.subscription.updated, payment_intent.failed—your system processes these in real-time, updating access and sending emails.
2. APIs for user actions: When customers view billing history or update payment methods, call Stripe's API directly.
3. APIs for backup: A nightly job polls Stripe to reconcile your database, catching any failed webhooks.

Webhook Reliability Challenges

Webhooks require operational complexity: your endpoint must be highly available. If it's down when a webhook arrives, you lose critical events. You need exponential backoff retries, signature verification against spoofing, and idempotency handling for duplicates. Managed webhook services handle this infrastructure—automatic retries, verification, delivery logs, and replay—letting you focus on business logic instead of infrastructure.

Making Your Decision

Here's a quick framework for choosing:

Choose APIs when:

• Users explicitly request data
• You're doing batch processing or reporting
• Update frequency is low (daily or less)
• You need precise control over timing

Choose Webhooks when:

• Real-time response matters
• Events are unpredictable or frequent
• You want to minimize resource usage
• You're integrating with modern SaaS tools

For startups deciding when to invest in webhook infrastructure, our guide on when startups should add webhooks provides a practical framework.

Use both when:

• You need real-time updates with guaranteed delivery
• You're building mission-critical integrations
• You want speed without sacrificing reliability

Conclusion

The choice isn't about a winner—it's about tradeoffs. APIs give control and simplicity; webhooks give speed and efficiency. Best integrations use both: webhooks for real-time events, APIs for data retrieval and recovery. As webhook technology evolves, these patterns become more critical.

Consider not just what's easiest today, but what scales with your needs. If webhook infrastructure management consumes more time than building features, it's time to use a dedicated service.