The most powerful backlinks comes from the relevant and quality website. A single backlink from a well authority and relevant sites are more valuable than the bunch of backlinks from an low-quality site. Here are some of the key metrics to establish the quality of the website to source the backlink.
Domain Authoiryt is the measure of the reputable ability of your website in its niche or industry on the scale form 0 to 100. The higher the domain authority of the website, more the valuable of it in the search engine. A backlinks from the good domain authority site will be more powerful enough to influence the positive result in your website in the search engine.
Citation Flow is another measure of ther website in the score between 0 to 100 and it is indicates the quality of the backlink pointing to. A website will have a high citation flow score if it has bunch of backlinks from the quality site. Likewise the flow value will drop if the website gets backlinks from the low-quality website. A backlink from a website with high citation flow metric may have good value.
Trust Flow metric of a website says about the quality of the website which is again scored between 0 to 100. A website will get high Trust Flow , if a number of quality backlinks points to it. A backlink from the good trust flow to your website is usually valuable.
The Spam Score is scaled from 0 to 17 which shows the probability of that website to be penalized in the search engine. A spam score below 5 is safe, so getting a backlink from the website who spam score is below five is valuable and good too.
Index Status from a website tells whether the site is indexed in the search engine or not. If a website is not indexed either it is penalized or robots.txt file is not configured correctly. A backlink from a website which is indexed only will pass the SEO juice to the pointing site if not it could even harm your website ranking.