A backlink checker answers one question: who links to a site, and are those links worth anything? The gap between tools is the size of the link index behind them and how much it costs to see the whole picture. The deepest indexes belong to a couple of incumbents that charge accordingly; a second tier delivers most of the same answer for a fraction of the price; and a few free checkers are genuinely useful for a quick look. We rated eight on index depth, how honestly each metric is explained, whether a real free check exists, and total cost once you add the rest of an SEO workflow. Here's the honest ranking, updated October 2026.
How we ranked
Index depth: how large and fresh is the link database behind the number?
Metric honesty: are authority scores explained, or sold as magic?
Free check: can you see real backlinks before paying?
Total cost: what do you pay once audit, keywords and rank tracking are included too?
Actionability: does it just list links, or help you act on toxic and lost ones?
#1
Ahrefs
Price: From $129/mo (Lite) · $449/mo (Advanced)
Best for: Teams whose work lives or dies on the largest, freshest link index.
Strengths
The deepest, most frequently-crawled backlink index in the industry — the benchmark everyone else is measured against.
Mature metrics (Domain Rating, URL Rating) that the whole SEO field already understands.
Excellent link intersect and competitor-gap tooling.
Weaknesses
Expensive, and the cheaper tiers cap the rows you can actually export.
No real free backlink check — you hit a paywall fast.
You still pay separately, in effect, for AI-search visibility, which isn't part of the core product.
Verdict
If raw backlink data is the core of your job and budget is not the constraint, Ahrefs is still the strongest single answer to "who links here." Most of this list exists because not everyone needs — or can justify — the deepest index at this price.
Best for: Marketing teams who want backlinks plus a very broad toolset in one bill.
Strengths
Large index, close enough to the leader for most SMB and agency work.
Backlink Audit with toxicity scoring and a disavow workflow built in.
Enormous surrounding toolset (advertising, PPC, social) if you'll use it.
Weaknesses
Pricier than Ahrefs at entry, so you switch for breadth, not savings.
The breadth is wasted money if you only need link checking.
AI-search citation tracking isn't native — it's a separate concern.
Verdict
Semrush is the right pick when the backlink checker is one of ten tools your team will genuinely use. If it's the only thing you need, you're paying for nine tools you won't open.
Best for: Founders and lean agencies who want backlink checking inside a full SEO + AI-visibility tool, not as a $139 standalone.
Strengths
A genuine free backlink checker — see real backlinks with authority, anchor text and dofollow status before paying anything.
Backlink checking, monitoring, site audit, keyword research and rank tracking are all in the same subscription, starting at $39.
AI-search (GEO) citation tracking is included in Pro — the thing the incumbents treat as a separate product.
Toxic-link flags and a disavow file generator come with the monitor, not a higher tier.
Weaknesses
The link index is smaller and less deep than Ahrefs or Majestic — for exhaustive link-gap analysis at enterprise scale, they still win.
Historical link data doesn't reach as far back as the decade-old incumbents.
Newer in the backlink category specifically, even though the wider platform is mature.
Verdict
Full disclosure: Outerank is our tool, so we've placed it honestly at #3. For the narrow question of "deepest possible backlink index," the incumbents win. But for "check your backlinks, monitor them, fix the toxic ones and run the rest of your SEO — including AI search — on one affordable plan," Outerank is the best value on this list. Start with the free backlink checker and decide for yourself.
#4
Majestic
Price: From $49.99/mo (Lite) · $399/mo (API)
Best for: Link specialists who live inside Trust Flow and Citation Flow.
Strengths
A link-only specialist with one of the largest historical link maps anywhere.
Strong for pure link-prospecting and neighborhood analysis.
Weaknesses
Link-only — no keyword research, audits, rank tracking or AI-search features.
The interface feels dated next to newer tools.
You'll need a second subscription for everything that isn't links.
Verdict
Majestic is a scalpel, not a suite. If your entire job is link analysis and you pair it with other tools, it's excellent. If you want one tool that also does the rest of SEO, it's only part of the answer.
Best for: Teams already invested in the Moz ecosystem and the DA metric.
Strengths
Domain Authority is widely quoted and easy to communicate to clients.
Clean, approachable interface for less technical users.
Reasonable link data for small-to-mid workloads.
Weaknesses
Smaller, less fresh index than Ahrefs, Semrush or Majestic.
DA is a relative score, often mistaken for a Google ranking factor.
Best value only if you use the wider Moz Pro suite.
Verdict
Moz is the comfortable, client-friendly choice. The link index isn't the deepest, but for agencies that report in DA and value simplicity, it does the job.
#6
Ubersuggest
Price: $29/mo or one-time lifetime
Best for: Solo site owners who want a quick, cheap backlink peek.
Strengths
The cheapest legitimate entry point, with a lifetime option.
Simple enough for a non-specialist to use in minutes.
Fine for a rough look at a small site's link profile.
Weaknesses
The smallest index here — misses many links the bigger tools find.
Metrics are coarse; not suitable for serious link-gap work.
Limited monitoring and no real toxic-link workflow.
Verdict
Ubersuggest is the "good enough for a quick check" option. For a hobby site or a one-off look it's fine; for ongoing professional link work you'll outgrow it quickly.
Editorial transparency
Disclosure: Outerank is our own tool, and we've ranked it #3 — not #1 — because the incumbents genuinely have deeper link indexes. We think honesty about where we win (value, all-in-one, AI search) and where we don't (raw index depth) is more useful to you than pretending otherwise.
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For a genuine free check that shows real backlinks with authority, anchor text and dofollow status, Outerank's free backlink checker is the most useful on this list — the big incumbents paywall their data quickly. For a rough look, Ubersuggest's free tier also works. The trade-off with any free checker is index depth: you see a sample, not the full link profile.
Which backlink checker has the biggest index?
Ahrefs and Majestic have the deepest, most historical link indexes, with Semrush close behind. If exhaustive link-gap analysis at scale is your job, those three are the honest answer. For everyday checking and monitoring at a fraction of the cost, value tools cover the same questions well enough.
Do I need a paid backlink checker?
For a one-off look, no — a free checker answers "who links to me?" For ongoing work — catching lost links, flagging toxic ones, tracking competitors — you need monitoring, which is where a paid tool earns its keep. The cheapest way to get both is a tool that bundles checking and monitoring rather than charging separately.
Is Domain Authority or Domain Rating a Google ranking factor?
Neither. DA (Moz) and DR (Ahrefs) are third-party scores that estimate link strength on a 0–100 scale. Google doesn't use them. They're useful for comparing sites relative to each other, not for predicting rankings directly.
How often should I check my backlinks?
A full check monthly is enough for most sites. What matters more is continuous monitoring in between — being alerted the day a hard-won link goes dead or turns nofollow, rather than discovering it a month later. That's a monitoring job, not a manual-check job.
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