How can I fix the 429 Too Many Requests error?

You can fix a 429 Too Many Requests error by reducing the number of API requests sent within a given time period and implementing a proper retry strategy. First, check the API documentation to understand its Cloud API Rate Limits and identify whether the limit applies per user, application, endpoint, tenant, or time window. If the response includes a Retry-After value, wait for the specified duration before sending another request. If no value is provided, use exponential backoff with jitter, gradually increasing the delay between retries. You should also reduce unnecessary API calls, control request concurrency, avoid sudden traffic spikes, and use batching where supported. For large Microsoft 365 migrations, implementing request throttling and automatic retries can help prevent repeated 429 responses while transferring mailboxes, OneDrive, and SharePoint data. A dedicated migration solution such as SysInfo Microsoft 365 Tenant-to-Tenant Migration Software can simplify this process by helping manage request pacing, throttling, and retry operations, reducing the need for administrators to handle these tasks manually.