When comparing Backlink indexes, it is essential to mind different approaches to building links databases. For example, they can be formed from several « subindexes » containing data of varying relevance. Let’s take a closer look at the differences in the architecture of the backlink databases of the abovementioned platforms.
Ahrefs’ backlink index is built with the following subindexes:
- Live – links that were found during the last crawl session and remain active until the subsequent crawling;
- Recent – the subindex contains data on active, as well as lost links that were listed as « live » for the last 3-4 months. This list may include the links that were marked lost due to technical reasons.
- Historical — all the links of the domain that have been assigned the « live » status, starting from 2016 (since the launch of the Ahrefs index). At the moment, these links might have lost relevance.
Semrush uses « fresh index ». It consists of links recorded during the last six months of crawling.
MOZ displays « fresh » data from the last crawl. Although the data is not updated for all links regularly — higher-quality pages are the first priority. The quality is determined by a machine-learning algorithm.
Majestic’s Index consists of the following parts:
- The « Fresh index » is all links considered active during the last crawl. The update rate is from 90 to 120 days.
- « Historical index » – in addition to fresh-index data, contains all links that have ever been detected within the analyzed domain.
Megaindex stores historical data on links since the launch of their own index in 2015.Serpstat backlink index only holds fresh links – those that were active within the last 70 days. This architecture allows updating the entire database for this period. However, if an active link is not found during the next check, information about it is stored for another six months in the « Lost Links » section. Therefore, users only get an up-to-date breakdown (whether it’s a competitor’s backlink profile or their own website).