Majestic Site Explorer has one of the largest and most complete databases of web links. They offer fresh and daily updated data, and it is very fast. They do make some data available for free although if you subscribe to the paid service you’ll get a lot more detail on your searches. This will provide you with extensive and in depth analysis that you will likely not be able to find anywhere else.
They do a really good job of determining the backlink sources to various sites as per the attached screenshot for an example on Majestic SEO’s website itself. Unfortunately our backlink profile is not super great at this point, so it would not be very interesting if we posted a screenshot for our own domain .
As the screenshot shows, there are quite a few backlinks available for perusal. I believe they do an excellent job of crawling the vast majority of the web in order to determine the full backlinks for their reports, including links that have low relevance or quality, which is really good to have available. Most other tools out there will not give you nearly as much data as Majestic SEO does.
Unfortunately most things in life are not free, as is the case with Majestic SEO. Their free plan is only available for site owners, but up from there you can get full access to their tool for a nomimal fee ranging from $30 to $250 per month.
They claim to have quite a few pages indexed. See for yourself!
>>> Visit Majestic SEO <<<