HTTP 509 Bandwidth Limit Exceeded — Unofficial Status Code

HTTP 509 Bandwidth Limit Exceeded is an unofficial status code used by some hosting providers when a website exceeds its allocated bandwidth. This guide covers everything you need to know about this topic, including common causes, step-by-step solutions, and answers to frequently asked questions.

Here are the key things to understand: Not an official HTTP status code — not defined in any RFC. Used by Apache extensions (bw_mod) and some hosting providers. cPanel and shared hosting commonly use this for bandwidth overages. The website remains accessible once the bandwidth resets (usually monthly). Some providers also use 509 when disk space is exceeded. Understanding these fundamentals will help you diagnose and resolve this issue more effectively.

The most common reasons this occurs include: Website traffic exceeded the hosting plan bandwidth allocation. Large file downloads consuming bandwidth rapidly. DDoS attack consuming all available bandwidth. Hot-linked images or files being served to external sites. Sudden traffic spike from social media or news coverage. Identifying the root cause is the first step toward finding the right solution.

To resolve this, follow these recommended steps: Contact your hosting provider to check bandwidth usage and limits. Upgrade hosting plan for higher bandwidth allocation. Implement a CDN (Cloudflare, CloudFront) to offload bandwidth. Optimize images and enable compression to reduce bandwidth per page. Check for hot-linking: configure .htaccess to block external image requests. If these steps do not resolve the issue, consider consulting additional resources or a qualified professional.

This article is part of our HTTP Status Codes collection on Error Codes Wiki. We provide comprehensive, up-to-date information to help you find solutions quickly.