Managing bot traffic: securing and optimising your website

Bots make up a significant share of web traffic, and not all of them are welcome. Some are essential - search engine crawlers, for example - but others consume your server resources without adding any value. In our article on Understanding Resource Usage, we compared a hosting server to a busy venue where every visitor, human or bot, uses a share of available resources. This article focuses on those bot visitors and how to keep them from degrading the experience for everyone else.

Why bots deserve special attention

Bots can affect your website in ways that are easy to overlook until the damage is done. Because they can request pages far faster than any human visitor, even a single aggressive bot can cause real problems:

• Server overload: A bot hammering your site with rapid requests forces your server to work harder, slowing page loads for genuine visitors.
• Resource drain: Bots consume CPU, memory, and bandwidth just as human visitors do. Sustained bot traffic can deplete these quickly, causing sluggish responses or timeouts.
• Potential downtime: In severe cases, heavy bot traffic can overwhelm your server entirely, taking your site offline.

1. Gatekeeping with robots.txt

The robots.txt file is the first line of control. It tells bots which parts of your site they may access and, for bots that respect it, how quickly they should crawl.

• Directing bot traffic: You can allow or block access to specific directories or pages, keeping sensitive or low-value areas out of reach.
• Crawl delay: For compliant bots, a crawl delay directive spaces out requests, reducing the load on your server at any given moment.

There are important limitations to be aware of:

• Compliance is voluntary: Malicious bots routinely ignore robots.txt. It offers no protection against scrapers or bots acting in bad faith.
• Googlebot ignores crawl-delay: Google's crawler does not honour the crawl-delay directive. If you need to reduce Googlebot's crawl rate, do so through Google Search Console, where you can request slower crawling during peak periods.

Robots.txt is a useful starting point, but it should not be your only measure.

2. Frontline defence with Imunify360

On Kualo's shared hosting, Imunify360 is active by default and provides robust bot protection at no extra cost.

Think of Imunify360 as a highly capable security team stationed at every entrance to your site. Its key capabilities include:

• Advanced detection: Real-time traffic analysis distinguishes harmful bots from legitimate ones using sophisticated algorithms.
• Automatic blocking: Malicious bots are blocked before they can access your site or consume your resources.
• Continual monitoring: Imunify360 watches your site around the clock, responding quickly to new and emerging threats.
• Web Shield: An additional layer that intercepts and inspects HTTP and HTTPS requests before they reach your site, filtering out malicious traffic so that only legitimate requests use your resources.

3. Extended bot management with Cloudflare

If bots remain a concern after Imunify360 is in place, Cloudflare adds a further layer of protection at the network perimeter - before traffic even reaches your server.

• Comprehensive bot management: Cloudflare uses global traffic data and machine learning to distinguish beneficial bots from harmful ones with a high degree of accuracy.
• Handling known crawlers: Cloudflare recognises legitimate crawlers such as Googlebot and allows them to index your site without interfering with your security posture. It can serve these crawlers cached content, reducing the resource cost of each crawl.
• Bot Fight Mode: Cloudflare's free plan includes Bot Fight Mode, which targets and mitigates common automated threats. Paid plans offer Super Bot Fight Mode for more sophisticated bot mitigation.

Using Imunify360 and Cloudflare together gives you defence in depth - Imunify360 handles threats at the server level while Cloudflare filters traffic before it arrives.

4. Caching to reduce bot impact

Caching is one of the most effective ways to limit the damage bots can do, because it removes the need for your server to generate a page dynamically on every request. LiteSpeed Cache is a strong option for WordPress sites and works as follows:

• Immediate response: Cached pages are served directly from storage rather than being built from scratch, which is significantly faster and far less resource-intensive.
• Reduced server load: Because the server skips the dynamic page-generation process, CPU and memory usage drop considerably - even when bots are making frequent requests.
• Cache warmer: LiteSpeed Cache includes a cache warmer that pre-loads cached versions of your pages after updates, so the cache is ready before the next request arrives.
• Consistent protection: Whether a bot is a legitimate search engine crawler or a malicious scraper, serving cached content means its visit has minimal impact on your server and on the experience of your human visitors.

Putting it all together

No single measure is sufficient on its own. The most resilient approach combines all four strategies:

1. Use robots.txt to guide compliant bots and manage crawl behaviour where possible.
2. Rely on Imunify360 as your primary server-level defence against malicious bot traffic.
3. Add Cloudflare for perimeter-level bot management and caching of crawler requests.
4. Implement caching with LiteSpeed Cache to minimise the resource cost of all bot visits.

Together, these layers keep your site secure, fast, and available - even under sustained bot traffic.