🆚 Clacks Overhead vs. Meta Robots
- 📈 Meta Robots is much more popular than Clacks Overhead.
- 🌍 Meta Robots is more popular in all countries.
- ⭐ Clacks Overhead is particularly popular in the United Kingdom.
Clacks OverheadType
About
Clacks Overhead is a feature based on the concept of semaphore towers from the Discworld fantasy book series written by Sir Terry Pratchett, an English author and humorist.
It was devised by 
Reddit users and allows websites to broadcast a message to the world via the non-standard X-Clacks-Overhead HTTP header. This message is usually dedicated to the memory of Terry Pratchett, reading "GNU Terry Pratchett", though it can contain any text.
Robots directives are instructions delivered through the robots meta tag or the X-Robots-Tag HTTP header that control how search engines and web crawlers index, cache, and process web content.
They can prevent pages from appearing in search results, restrict link crawling, limit cached copies and search snippets, control image previews, and are recognized by major search engines including 
Google and Bing.
Headquarters
Popularity
Determined by the number of sites using each technology.
Market share
Popularity by country
Determined by the number of sites detected from each country.
Popularity by domain category
Determined by the number of sites in each category.
Top sites
Top-ranked sites that use these technologies.
Compare alternatives
Technologies with similar characteristics.
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IETF company profile🗃️ About This Data
- We evaluate the popularity of technologies based on the number of websites where we detect their usage.
- Technologies without a detectable web footprint, and those we do not track, are not reflected in the calculated market share.
- This report is based on the analysis of 3,524,018 websites.
- Statistics were last calculated on .
- For more details, see our methodology and disclaimer.