Ahrefs

Ahrefs is the tool to buy if link data matters, and for most SEO work it does. Its crawler is second only to Google's among tools we tested, and the index shows links faster and more completely than rivals — in our checks it surfaced new links days before the alternatives and retained historical data others had dropped.

The interface deserves separate credit. Where Semrush presents dozens of overlapping reports, Ahrefs is organised around the questions people actually ask: who links to this, what does this site rank for, what changed. Site Explorer, Keywords Explorer and Site Audit each do one job well, and new users become productive far faster than the feature count suggests. Its keyword difficulty scores also tracked our verified Search Console data more closely than any other tool's.

The friction is commercial. There is no free tier and no trial, so evaluation means paying. The Lite plan at $108 a month is genuinely limiting — fewer credits than a working SEO burns through in a fortnight — so the real entry price is Standard at $208. Credits meter almost everything, and running out mid-month is the most common complaint from its own users.

Our guidance: the default choice for anyone doing serious organic work, and worth the money. Choose Semrush instead if you need paid search and PR in the same subscription, and Moz if the budget genuinely does not stretch.