This is anthropic.com's real off-page authority, straight from the Semrush export. And it's good news: an Authority Score of 69 and rising, 123,340 referring domains, 9.77M backlinks, and a profile Semrush itself flags as natural and healthy — links from nytimes, the guardian, nasa.gov. Authority is the one plane where Anthropic is winning. The catch is two-fold: it's still 30 Authority-Score points behind OpenAI, and — as the other planes show — this equity isn't being converted into rankings or AI citations.

The same four domains as every other module. On authority, the order flips from the traffic leaderboard in one telling way: claude.com (AS 67) is right beside anthropic.com (AS 69) — your own two properties split the equity — while OpenAI sits at a near-perfect 99 with 3.4× your referring domains and 6.4× your backlinks.

Semrush gives you a 69 and stops. We don't. Authority Score is built from four measurable inputs — here's exactly where Anthropic stands on each, and which one is the lever. Two are strengths (naturalness, momentum); two are the gap (link power, link quality). The score moves when you fix the quality input — not by chasing raw link count.

123K referring domains sounds close to OpenAI until you sort them by authority. Anthropic has just 183 referring domains in the elite AS 81–100 tier — OpenAI has 386, 2.1× more. The bulk of every profile is low-authority (AS 0–20), but the top of the pyramid is what moves the score — and that's exactly where the gap is widest.

The momentum is real and positive: Anthropic is adding referring domains faster every month, accelerating to roughly 4,400 new domains a fortnight by June — the opposite of the keyword-ranking decline. The link sources skew toward top-tier media (your strongest signal) but lean thin on Education, where you trail OpenAI nearly 2:1.

Not a decoration — a map of how the web actually links to you. The core is anthropic.com; the inner ring is the real pages that earn the links (your careers page and homepage pull the most), sized by link volume; the outer nodes are the referring domains, sized by Authority Score, coloured by category, each wired to the page it points at. Hit vs OpenAI to see the authority gap as a picture — their web is 3.4× denser.

226,590 unique anchor texts. The healthy signal: "anthropic" is your top brand anchor across 25,623 different domains — natural, diverse, exactly what Google wants to see. The watch-item: "claude claude" has more raw links (991K) from just 46 domains — a single-source concentration worth monitoring, not a penalty.

A natural, follow-heavy profile: 87% text links, 81.6% follow — the equity-passing kind. The action hiding here: 23,133 links are "Lost & Vital" — high-value links you used to have and dropped. Reclaiming a lost link you already earned is the cheapest authority you'll ever buy.

A backlink audit asks the opposite question: is any of this hurting you? Semrush's verdict on anthropic.com is Overall Toxic Score: MEDIUM — and the detail is reassuring. Of the audited sample, 90% of referring domains are clean; only 1% (114 domains) are toxic and 9% (768) potentially toxic. No manipulation problem — just a short, finite disavow list and 1,001 broken links worth reclaiming.

Proof this is real link-level data, not a rollup. A sample of recent backlinks with their source authority, the exact anchor, and where they point — the rawest layer of the profile.

160,074 referring domains link to your competitors but not to anthropic.com — Semrush's Backlink Gap. These are pre-qualified prospects: they already link to AI labs, so the pitch is warm. Scored by opportunity (authority × topical relevance × reach); 12 here are universities, your most under-indexed and highest-trust class. Click any prospect for the play.

This is what a standalone backlink tool can't tell you. Your link profile isn't a vanity metric — it's the fuel for three other planes. Here's exactly how 9.77M backlinks feed entity trust, AI citations, and organic rank — and why the equity is currently built but not converted.