A ‘429 concurrency_limit_exceeded’ error means too many of your scrape requests are running at the same time. Your account has a concurrency limit, and a new request that goes over it is rejected. Requests rejected for this reason don’t use credits.
Here’s how to fix it:
Retry after an active request finishes. As soon as one of your requests completes, there’s room for a new one.
Wait longer between retries. If the error repeats, wait 2, then 4, then 8 seconds between attempts, adding a short random delay each time.
Run fewer requests in parallel. Keep the number of active requests below your concurrency limit.
How to Check Your Concurrency Limit
Use the User endpoint (GET /v1/user). The ‘concurrency_limit’ value shows how many scrape requests you can run at the same time. If you usually need to run more requests at once, contact IPRoyal Support to increase your concurrency limit.
Learn more about limits and retries in our Web Scraper API documentation.