Authority Score is a third-party SEO metric used to check how strong or trustworthy a website is. It works on a scale of 0 to 100. A higher score means the site is more likely to rank in search engines. This score is based on backlink quality, organic traffic, and spam signals.
It was created by Semrush, a well-known SEO platform. Other SEO tools like Ahrefs and Moz offer similar scores, called Domain Rating and Domain Authority. These are not official Google ranking factors, but they help compare websites using public data like link profiles and search visibility.
Authority Score is used in search engine optimization to check how strong a website looks to search engines. It helps compare websites based on their SEO strength, credibility, and ranking potential.
Many SEO professionals use Authority Score to:
- Compare one site with another
- Check if a domain is likely to rank
- Find out which sites have better backlink profiles
- Track if a site is improving or falling in search strength
This score does not show guaranteed rankings, but a higher number often means better visibility in search.
Authority Score helps during link building. When choosing websites to get links from, SEO experts often check this score. A link from a high-authority website usually passes more SEO value than one from a lower-rated site.
Competitive research and content strategy
Marketers also use Authority Score to study their competitors. They check why a rival site ranks better—maybe because it has stronger links or more trusted content. Some teams use it to decide which pages to improve first. Pages on high-authority domains are often updated or promoted first, as they are more likely to rank.
Tracking SEO growth
Many SEO agencies track this score over time for each website. If the score goes up, it may mean the site is gaining better links or traffic. If it drops suddenly, it could mean lost links or slow content. These changes help teams act fast and improve performance.
Website quality check
In partnerships, some website owners check Authority Score before working with another site. It helps avoid linking with sites that may be low quality or flagged as spam.
The score is a quick tool to judge a site’s trust, authority, and search power within its field.
Authority Score is calculated using a mix of link signals, traffic estimates, and spam checks. These signals are weighted differently and combined using a machine-learning model. The system follows a logarithmic scale, which means higher scores become harder to earn over time.
1. Backlink quality and quantity
The most important part of the score comes from backlink signals. These include:
- How many external websites link to the domain
- How strong or trusted those linking sites are
- How natural the link profile looks
A site with many high-quality incoming links has more link power. This idea is similar to how Google PageRank worked, where links act like votes from trusted websites.
2. Organic search traffic
Traffic from search engines also affects the score. If a site ranks well for valuable keywords and brings in real visitors, the score may rise even if the site has fewer links. This means organic search traffic can improve a site’s authority when users engage with the content.
Semrush estimates this traffic based on:
- Number of keywords the site ranks for
- Search volume of those keywords
- Click-through rates from search results
3. Spam and manipulation indicators
Several checks are used to flag unnatural SEO signals. These include:
- A site with many links but no organic keywords
- Too many follow links (over 90 percent), suggesting link schemes
- A mismatch between link volume and actual traffic
- Large groups of links coming from the same hosting network
- Duplicate link patterns across domains (e.g. mirror sites)
Any of these may lower the score if the system detects link manipulation or SEO spam.
4. Weight and scoring model
Each part of the formula has its own weight:
- Backlink strength is the most important
- Organic traffic comes next
- Spam risks are used to adjust or suppress the score
The scale is not linear. For example, going from a score of 10 to 20 is easier than jumping from 50 to 60. Only top sites like government portals or global news networks score near 100. Most small or mid-level sites fall between 20 and 60.
Summary of key signals
Sites with quality backlinks, trusted referring domains, and steady organic search traffic tend to have higher Authority Scores. Low scores are often caused by link spam, fake signals, or little real traffic.
The idea of Authority Score comes from early search engine models that used link analysis to measure how important a page was. One of the first systems was the HITS algorithm, which gave each page two values: a hub score (based on outgoing links) and an authority score (based on incoming links). Google later used a similar idea in its PageRank system, which ranked web pages by looking at the number and quality of links pointing to them.
Google stopped showing PageRank scores publicly. After that, SEO tools started offering their own authority-based metrics. Semrush created Authority Score to help fill this gap and continued refining it over time.
In January 2023, Semrush updated the Authority Score system. The new version added more weight to two areas:
- Organic search traffic, showing how much real visibility a site has
- Spam risk indicators, detecting if a site might be using fake or low-quality links
Before this update, the score mostly focused on backlink quantity and quality. The newer version looks deeper at a site’s true impact, not just its links. Some niche websites saw their scores drop after the update. Others, like broad-topic websites with more search reach, saw gains.
This update aligned with growing attention to trust, content quality, and signals seen in Google’s E-E-A-T guidelines (Experience, Expertise, Authoritativeness, Trust).
Authority Score is one of several tools used to measure a site’s SEO strength. Others include:
| Metric | Provider | Primary basis | Scale |
|---|---|---|---|
| Authority Score | Semrush | Backlink quality, organic traffic, spam signals | 0–100 |
| Domain Authority | Moz | Backlink count and quality, using a machine model | 0–100 |
| Domain Rating | Ahrefs | Referring domains and backlink quality only | 0–100 |
| Trust Flow | Majestic | Trustworthiness of backlink sources | 0–100 |
Each score uses its own system, but all aim to show how likely a domain is to rank. For example:
- Domain Rating by Ahrefs looks only at link strength
- Domain Authority by Moz uses predicted ranking ability
- Trust Flow checks the quality of link sources
After the 2023 update, Semrush’s Authority Score became more resistant to SEO manipulation by combining traffic, link trust, and spam filtering. While their formulas differ, SEO experts often treat these metrics as relative indicators of site authority in backlink analysis and competitive research.
Authority Score is a helpful tool in SEO analysis, but it must be used with clear understanding. While it measures a site’s backlink strength and visibility, it is not part of Google’s official ranking system.
Search engines like Google do not use Authority Score, Domain Rating, or Domain Authority in their algorithms. These scores are built by SEO platforms to reflect a site’s likely strength, but Google does not look at these numbers.
However, the factors that shape Authority Score—such as the number and quality of backlinks—do match what Google’s algorithm values. This creates a correlation, not causation. A high score often signals that a site has many good links, which can help it rank better in search.
There is no fixed number that defines a “good” score. A score of 30 might be strong in a small niche where most sites score near 20. The same number would be weak in a competitive industry where top sites score over 70. That is why the score should always be read in context, compared with other sites in the same topic area.
It is not a performance goal
Authority Score is not a target. It is a diagnostic signal. Trying to raise it by any means—especially using unnatural backlinks—can backfire. The score includes spam detection, so manipulative tactics may lower the score instead of helping it.
It does not measure relevance
Even with a high Authority Score, a site can lose in search if it does not meet search intent. A site with a lower score may still outrank a higher-scoring one if its content is more topically relevant and offers better user experience.
The score does not show how relevant a site is to a specific query. It only reflects general authority across the web.
Summary of practical use
SEO teams often use Authority Score to:
- Spot spam or unusual drops
- Compare domains during outreach
- Benchmark strength in a niche
It should be used alongside other factors like content quality, topical depth, and technical SEO. A balanced strategy looks beyond the score to the full picture of what makes a site rank.
Reference
- https://www.semrush.com/blog/semrush-authority-score-explained/
- https://www.semrush.com/kb/747-authority-score-backlink-scores
- https://huble.com/blog/semrush-authority-score-update-2023
- https://help.ahrefs.com/en/articles/907673-do-search-engines-use-domain-authority-domain-rating-as-a-ranking-factor
- https://agencyanalytics.com/kpi-definitions/authority-score
- https://www.semrush.com/blog/new-authority-score-manipulation-resistant-metric/
- https://juicify.digital/blog/decoding-domain-authority/
- https://en.wikipedia.org/wiki/HITS_algorithm
- Fallow Us on:
