What Domain Strength Actually Measures

Domain strength is a third-party score, usually shown on a scale from 0 to 100, that estimates how much link power a website can pass on to the pages it links to. It is not a Google metric, and Google has never confirmed that it uses anything like it. Instead, tools build the number by crawling the web, mapping which sites link to which, and then weighting those links by the strength of the sites doing the linking. The result is a rough proxy for authority.

Most tools calculate something similar but label it differently — you may see it called domain authority, domain rating, authority score or trust flow. The names vary, the underlying idea does not. A site with a high score has attracted links from other strong sites over time, which usually means it has been around a while, publishes content people want to reference, and carries some weight in its niche.

What the score is not is a measure of how good a business is, how much traffic it gets, or how likely it is to accept your guest post. Treat it as one signal among several, not a verdict.

Why It Matters Most When You're Pitching

If you run a small business and you are building links yourself, your scarcest resource is time. Every pitch you send costs you an hour you could have spent on clients. So the value of domain strength is largely practical: it lets you sort a long list of possible targets into "worth a closer look" and "probably not" in a few minutes.

Before you spend twenty minutes writing a personalised email to a blog editor, you want a rough idea of whether the site is a real, established publication or a link farm with a hundred thin articles and a score of 3. Domain strength does that job quickly. It also protects you in the other direction: if a site with a score of 80 in your niche approaches you and asks for a fee, you will know why it is asking, and you can decide whether the placement is worth the money.

It is also useful for comparing your own site against competitors. If three local rivals all sit in the 20s and you are on 6, that gap tells you something about the work ahead — not the whole story, but a starting point.

How to Read the Numbers in a UK Context

Scores are easier to interpret in bands than as precise figures. A rough guide for small business work:

• 0–10: Very new or very small. Links from here carry little weight on their own, though a local niche site with genuine relevance can still be worth having.
• 11–30: Typical of established small business websites, local blogs and trade publications. This is where most realistic link building happens for a UK SME.
• 31–50: Strong regional or sector publications, well-run independent blogs, some trade magazines.
• 51–70: National media, large industry bodies, major sector sites. Hard to win, worth trying.
• 71+: Household names and major publishers. Realistically out of reach without a genuinely newsworthy story.

The band matters less than the comparison. A score of 28 is unimpressive next to a national newspaper but excellent next to everything else in your postcode. Always judge a target against other sites in the same niche.

Where the Metric Falls Short

Domain strength is an estimate, and estimates have blind spots. A few things to keep in mind:

• It measures the whole domain, not the page. A strong homepage says nothing about whether an article buried in a subfolder is indexed or read.
• It lags behind reality. Scores update on their own schedule, so a site that has just lost its best writers may still look healthy.
• It can be gamed. Paid link networks inflate scores, which is exactly why a high number plus obvious spam is a red flag rather than a green light.
• It ignores relevance. A score of 45 on a site about gardening is worth far more to a garden design business than a score of 60 on a general news site.
• It ignores traffic. A site can rank well and get visitors without ever accumulating links, and vice versa.

A Practical Pre-Pitch Checklist

Before you write to anyone, run through these four checks in order. It takes about two minutes per site and saves a great deal of wasted effort.

• Check the domain strength and note the band it sits in.
• Read the last six articles. Are they well written, current and relevant to your audience?
• Look for obvious link selling — footers stuffed with unrelated commercial links, sponsored posts labelled as editorial, or a scatter of topics that make no sense together.
• Ask whether a real person would click through from that page to your site, and whether you would be happy for a customer to see it.

If a site passes all four, pitch it. If it fails on relevance or quality, no score is high enough to make it a good use of your time. Domain strength is a filter, not a finish line — use it to narrow the field, then rely on judgement for the decision that actually matters.