API Rate Limiting

API Rate Limiting

What Is API Rate Limiting?

API rate limiting is the practice of restricting how many requests a client, token, user, or IP address can send within a defined time window. It is commonly used to protect APIs from abuse, overload, and unfair resource consumption.

Why API Rate Limiting Matters

Rate limiting helps teams:

• Protect service reliability during spikes or abuse.
• Reduce denial-of-service exposure and noisy client behavior.
• Preserve fair usage across tenants, integrations, or users.
• Control infrastructure cost when traffic grows unexpectedly.

How API Rate Limiting Is Applied

Typical implementations define limits by endpoint, account tier, token, or IP address. When a client exceeds the threshold, the API usually rejects the request with an HTTP 429 Too Many Requests response and may include retry guidance.

Good rate limiting works best when paired with:

• clear API documentation,
• monitoring and alerting,
• burst handling rules,
• observability into rejected traffic.

Related Terms

• Observability
• Incident Management
• Service Level Objective