GlossarySEO
What is the Tranco rank?
Also called: Tranco list, Tranco ranking, top sites list
Definition
Tranco is a research-oriented list of the world's most popular websites, built by combining several independent popularity rankings and averaging them over 30 days to resist manipulation. A site's Tranco rank is its position in that list.
Tranco rank, explained
Tranco was created by researchers Victor Le Pochat, Tom Van Goethem, Samaneh Tajalizadehkhoob, Maciej Korczyński and Wouter Joosen, and presented at the NDSS security symposium in 2019. The paper's title explains the motivation: a top-sites ranking hardened against manipulation. Researchers had relied on lists like Alexa's, which were easy to game and changed wildly from day to day.
Tranco's site lists its current providers: Cisco Umbrella, Majestic, Farsight, the Chrome User Experience Report (CrUX) and Cloudflare Radar. CrUX and Cloudflare Radar were added in August 2023, and the Alexa ranking was removed after it was discontinued. The standard list is one million domains obtained by averaging the rankings over the past 30 days, updated daily, with permanent IDs so research can be reproduced.
For founders and marketers, Tranco is a neutral, free popularity signal. It's useful for sanity-checking a directory or publication's reach: a site in the top 100,000 is almost certainly a real, visited site; one missing from the top million is small. Launch platforms and directory lists sometimes show it for that reason.
Know its limits. Tranco measures popularity at the domain level, not relevance, quality or search visibility. It says nothing about whether a site's links are followed or whether its audience matches yours. Positions below the top few hundred thousand are noisy, and ranks for small sites move a lot. It's one input, not a score to chase.
It's also not an SEO authority metric like Domain Rating. A popular site with few links can rank well in Tranco, and a heavily linked niche site can be absent.
Why it matters for founders
When choosing directories, publications or partners, a Tranco rank is a quick, free way to check that a site has real visitors, without relying on a vendor's link-based score.
Example
A founder shortlisting directories checks each one's Tranco rank. Two with impressive Domain Ratings aren't in the top million at all, suggesting few real visitors, so they drop down the list.
Common mistakes
- Treating Tranco rank as a measure of SEO authority.
- Reading small rank changes for small sites as meaningful.
- Choosing a directory on popularity alone, ignoring audience fit.
Sources
- Tranco: A research-oriented top sites ranking hardened against manipulation
- Le Pochat et al., Tranco (NDSS 2019)
Checked
Related terms
- Traffic estimatesTraffic estimates are modeled guesses of a website's visits made by third-party tools like Similarweb, Ahrefs and Semrush. They're built from panels, partner data and rankings, not from the site's own analytics, so treat them as rough.
- Domain authority (DA and DR)Domain Authority (Moz) and Domain Rating (Ahrefs) are third-party scores, roughly 0 to 100, estimating the strength of a site's backlink profile. They are SEO tool metrics, not Google metrics, and Google doesn't use them.
- Directory submissionDirectory submission is listing your product on curated websites that catalog tools and startups by category. Good directories give a new site early links, consistent brand citations and some discovery traffic.
- Referring domainsReferring domains are the unique websites that link to your site. Ten links from one site count as one referring domain, which is why SEO tools treat referring domains as a better measure than total backlinks.