Trust Flow vs Domain Authority vs Domain Rating: Which Metric Matters?
Every expired domain listing wears three badges: a Trust Flow from Majestic, a Domain Authority from Moz, a Domain Rating from Ahrefs. Buyers routinely pay hundreds of dollars more for a domain because one of those numbers is high, and none of the three comes from Google or predicts Google. This guide explains what each metric actually computes, where each one lies to you, and the triage sequence that keeps a shiny score from emptying your wallet.
What does each metric actually measure?
Trust Flow and Citation Flow (Majestic)
Majestic scores every domain twice on 0-100 scales. Citation Flow measures link volume: how much raw linking power points at the name, junk and gold counted alike. Trust Flow measures quality: how close the domain sits, through links, to a hand-reviewed set of trusted seed sites. The two are designed to be read together, and their gap is the message. A domain with CF 40 and TF 8 is announcing that its links are plentiful and untrusted, the classic residue of link schemes. Majestic also breaks trust down by subject as Topical Trust Flow, which tells you whether a "fitness" domain's authority actually came from fitness sites.
Domain Authority (Moz)
Domain Authority is Moz's 0-100 machine-learning estimate of how likely a site is to rank relative to others. It was built as a comparative metric, which is the part buyers forget: DA 30 means little in isolation and a lot when every competitor in the niche shows DA 15. It refreshes roughly monthly, so a freshly spammed or freshly cleaned domain can wear an outdated score for weeks. Moz pairs it with Spam Score, the share of spam flags a domain trips, where under 10% is generally treated as clean.
Domain Rating (Ahrefs)
Domain Rating is the Ahrefs 0-100 measure of backlink profile strength, driven by referring domains and their own strength. Its distinguishing feature is speed: DR refreshes about every 12 hours, against roughly monthly for DA. That freshness cuts both ways, showing you genuine link growth quickly and reflecting bought link bursts just as quickly. In expired domain circles DR is the most quoted number, which also makes it the number sellers work hardest to inflate.
| Metric | Vendor | What it rewards | Refresh | Blind spot |
|---|---|---|---|---|
| Trust Flow | Majestic | Proximity to trusted seed sites | With Majestic index updates | Says nothing about link volume on its own |
| Citation Flow | Majestic | Sheer linking power | With Majestic index updates | Counts junk links as happily as good ones |
| Domain Authority | Moz | Comparative ranking potential | Roughly monthly | Slow to reflect recent spam or cleanups |
| Domain Rating | Ahrefs | Backlink profile strength | About every 12 hours | Fast refresh mirrors fresh link spam fast |
How far apart can the same domain score?
Further than most buyers believe: authority scores from different tools differ by about 26 points on average for the same site. That is not a rounding disagreement; it is the difference between "premium asset" and "hard pass" delivered by two dashboards describing one domain. The spread exists because each vendor runs its own crawler, its own index, its own math and its own refresh cycle. An illustrative example: a domain shows DR 45 and DA 19. Neither is wrong. Ahrefs is reporting a link profile that grew recently and fast; Moz is reporting that the growth has not translated into the comparative signals it models. The disagreement itself is the finding, and it should send you to the backlink data, not to the average of the two numbers.
The TF:CF triage rule
The fastest quality filter in the business is a division. Take Trust Flow over Citation Flow: a ratio below roughly 0.3 is a red flag, marking domains whose link volume massively outruns their trust. Healthier profiles sit closer to balance. The rule earns its keep in bulk: run it across a 500-domain shortlist and the bottom third usually disqualifies itself before you open a single backlink report. Treat it strictly as triage. A good ratio does not certify a domain, and niche quirks can produce false alarms, but a bad ratio almost always means what it looks like it means.
The worked example from the text, drawn: plenty of link volume, very little trust, exactly the shape the TF:CF triage rule exists to catch
Can these metrics be manipulated?
Yes, and expired domain sellers are the world's most motivated practitioners. Volume metrics move easiest: cheap link blasts pump Citation Flow and can lift DR within its 12-hour refresh window. Trust-weighted scores resist longer but bend under links from compromised or rented pages on trusted sites. This is why single-metric buying fails, and why the counterweights matter: Moz Spam Score under 10%, the TF:CF ratio, anchor text that reads like a real site earned it, and archived snapshots showing coherent history. The metrics were built to describe honest sites; on expired inventory, assume every number was potentially dressed for the sale until the raw evidence agrees with it.
A sane vetting stack
- Triage: TF:CF at or above roughly 0.3, plus a referring domains count that justifies interest. Definitions for every term here live in our 60-term glossary.
- Corroborate: check at least two vendors, expecting the 26-point spread; investigate disagreement rather than averaging it.
- Spam screen: Moz Spam Score under 10%, or an SZ score pass if you run SpamZilla; our DomCop vs SpamZilla comparison covers that layer.
- Read the anchors: commercial and foreign-language anchor stuffing outranks any score as a warning.
- Replay the history: Wayback snapshots, because the links only matter if they survive scrutiny, as our guide to whether expired domains keep their backlinks explains.
Tooling note: aggregators such as DomCop print Majestic and Moz data side by side on every listing, which makes steps one through three a single screen instead of three subscriptions.
Frequently asked questions
Which metric does Google actually use?
None of them. TF, DA and DR are third-party estimates built from each vendor's own crawl of the web. They correlate with ranking ability at best. Google's own link-based signals are internal and unpublished.
What is a good Domain Rating for an expired domain?
There is no universal threshold. A DR 20 with 150 genuine referring domains in your niche beats a DR 45 built on rented links. Judge scores relative to the niche and always alongside the referring domains count and anchor profile.
Why do Domain Authority and Domain Rating disagree so often?
Different crawlers, indexes, models and refresh cycles: DR updates about every 12 hours, DA roughly monthly. An average gap of about 26 points between tools is normal, which is exactly why quoting one score without naming the vendor is meaningless.
Is Trust Flow the best metric for expired domains?
It is the best single quality signal because it is hardest to fake quickly, but it answers only one question. Use TF for trust, CF and DR for scale, DA for competitive context, and the spam scores plus Wayback for the truth.