Short answer: Moz DA predicts ranking ability, Ahrefs DR measures backlink strength, and Majestic Trust Flow measures how closely a site is linked to trusted sources. They use different link databases and formulas, so the numbers never match. Use DR or DA as your main authority metric and Trust Flow as an extra quality check.
The three metrics in one table
| Moz DA | Ahrefs DR | Majestic TF | |
|---|---|---|---|
| Scale | 1–100 | 0–100 | 0–100 |
| Measures | Predicted ability to rank | Strength of the backlink profile | Link “trust” relative to seed sites |
| Main input | Linking root domains and other signals, via a machine-learning model | Unique followed referring domains and their DR | Distance from a hand-picked set of trusted sites |
| Best for | Reporting, broad comparisons | Link building and buying decisions | Spotting link quality issues |
Moz Domain Authority (DA)
DA is Moz’s score for how likely a domain is to rank compared with others. It is produced by a model trained on Moz’s link index and real search results. Because it is a prediction, it can respond to more than raw link counts. Many agencies use DA in client reports because it is widely recognised.
Ahrefs Domain Rating (DR)
DR focuses purely on the backlink profile: how many unique websites link to you with followed links, how strong those sites are, and how many other sites they link to. It is simple to understand, widely quoted by link sellers, and easy to verify in bulk with a bulk DR checker.
Majestic Trust Flow (TF) and Citation Flow (CF)
Majestic offers two related metrics. Citation Flow reflects the volume of links pointing to a site. Trust Flow reflects how closely those links connect back to a set of manually selected trusted websites. Many SEOs look at the ratio between them: when Citation Flow is much higher than Trust Flow, the site may have lots of low-quality links.
Why the numbers differ
- Separate crawlers: each company discovers a different slice of the web.
- Different goals: prediction (DA), strength (DR) and trust (TF) are different questions.
- Different update cycles: one index may reflect recent changes sooner than another.
A site with DR 50, DA 35 and TF 20 is not contradictory. It simply looks different through three lenses.
Which one should you use?
- Buying guest posts or links: use DR as the main filter, because most vendors quote it and you can verify it quickly.
- Client reporting: use whichever metric your clients know – often DA or DR – and stay consistent.
- Quality checks: add Trust Flow when you suspect a site has many low-quality links.
Warning signs when metrics disagree
- High DR, very low TF: many links, few trusted ones. Check for link networks.
- High DA, low DR: possibly older or differently weighted link data. Re-check the links.
- All three high, but no traffic: a classic sign of an expired or penalised domain. See DR vs traffic.
None of them is used by Google
Google does not use DA, DR or TF. They are third-party estimates of the same thing Google values – links from real, trusted websites. Treat them as research tools, not goals. Improving the underlying link profile is what helps rankings.
Practical workflow
- Bulk-check DR for your whole list in the DR checker.
- Remove sites below your minimum and check the rest in the free Domain Age checker.
- Check Trust Flow for the sites that remain if you want an extra quality signal.
- Review traffic, relevance and content by hand before you pay.
Example: one site, three numbers
A home-improvement blog shows DA 38, DR 52 and TF 24. What does that tell you? DR is the highest because Ahrefs has found many unique followed referring domains. DA is lower because Moz’s model weighs other signals and its index may contain fewer of those links. Trust Flow is moderate, suggesting a mix of trusted and ordinary links. None of this is a problem. If the site is relevant to you, gets steady traffic and publishes real content, it is a reasonable link opportunity – the three numbers simply describe it from different angles.
How to report authority to clients
Pick one primary metric, explain in one sentence what it measures, and show its trend over time next to organic traffic and conversions. Clients care about results, and a single, consistent metric avoids confusing conversations about why three numbers disagree.
Frequently asked questions
Which metric do link sellers use most?
Ahrefs DR is the most common in guest post and link marketplaces, followed by Moz DA.
What is a good Trust Flow?
It depends on the niche. Many SEOs look for Trust Flow that is not far below Citation Flow as a sign of healthy links.
Should I track all three metrics?
Track one as your main metric. Use the others when you need a second opinion on an important decision.
Final thoughts
All three metrics are useful when you understand what each one measures. Choose one as your main yardstick, use the others as cross-checks, and always look at the real site. For the most common comparison, read DR vs DA.