Backlink APIs you can pay per call

What a backlink API returns

A backlink is a link on one site that points to a page on another. A backlink API reports those links for a domain or a URL, drawn from an index the provider builds by crawling the web or licenses from someone who does. The answer can be a summary, such as the number of links and the number of distinct sites they come from, or a list of the linking pages with details for each link.

Two counts are easy to confuse. The number of backlinks counts every link, so one site with a link in its footer can contribute thousands. The number of referring domains counts distinct sites, which is closer to the breadth of a profile. A report that gives both, and lists the top referring domains, lets an agent tell a broad profile from a narrow one with many repeated links.

Per-link details decide what you can do with the data. Anchor text shows how other sites describe the page. A follow or nofollow attribute shows how the link is marked. First-seen and last-seen dates show when the index discovered a link and when it last confirmed it. Without them, a list of linking sites supports a quick review but not an outreach plan or a cleanup.

No crawler sees the whole web, and every index adds and drops links on its own schedule. Two providers can report different totals for the same domain on the same day without either being wrong about what it found. Treat a backlink report as a sample from one index, dated, rather than a census of every link.

Backlink profiles, authority scores and organic context

Endpoints are classified by what their descriptions say they return. A backlink profile, with totals or referring domains for a domain, is the product that qualifies a service for this page and supplies its row price. A link-graph authority score is a different product: it condenses links into one number and lists no linking pages. A domain's organic footprint, with ranked keywords and estimated traffic, is context for the same domain. Both are shown beside a qualifying service, but they never qualify it on their own or supply its row price.

The page lists services whose own listing describes backlink data. Link reports sold inside broader SEO packages are compared on the SEO API and best SEO API pages, together with audits, keyword data and search results.

Each price is the cheapest endpoint of that service for that kind of data: the same number wherever this page quotes it.

Scope claims come from the matched endpoint descriptions:

• Backlink totals or summary metrics are returned by Citable.
• Top referring domains are returned by Citable.

A description that names a field promises that field; it does not say how deep the list goes or how recently the index was refreshed.

Compare 1 backlink API

Each row is priced on the cheapest priced backlink-profile route, with the path printed under the price. Rows are ordered by distinct paying wallets over 30 days, a measure of use rather than index quality.

$/CALL is the price of the endpoint named under it: the cheapest backlink profile of a domain endpoint of the service or, for a service without one, its cheapest backlink endpoint. Never the cheapest tool of a gateway. Other kinds of data have their own price in the tables below. BACKLINK ENDPOINTS counts the backlink endpoints out of all the endpoints the service lists. BUYERS 30D counts distinct wallets that paid the whole service on-chain in 30 days, not only its backlink endpoints. "Generalist" marks a gateway that sells more than three unrelated kinds of tools: it is never called the cheapest.

How to choose a backlink API

Check the depth of the answer

A summary with top referring domains suits a quick comparison of competitors. An audit or an outreach plan needs the full list of linking pages, with pagination and per-link fields. Ask how many rows a call returns and whether more cost another call.

Ask about freshness

Indexes recrawl pages at different rates. A link removed last week can still appear, and a new link can take time to show up. Look for first-seen and last-seen dates, or an index date, and record them with every result.

Test against links you know

A practical check is your own site. Compare the provider's list with links you can confirm, for example from your search console or from partners who link to you. Missing known links show the limits of the index; links you cannot find on the referring page show stale entries.

Keep units apart

Backlinks, referring domains, referring IPs and authority scores are different units. Store them in separate fields and never add totals from two providers together.

Plan repeat calls

The median monitored uptime of the listed services is 100%. Monitoring checks the payment endpoint, not how long a large report takes, so time the calls you will repeat on a schedule.

Which endpoint fits which job

Pick the job by the output your next step consumes. Candidates come from the same endpoint classification as the table, and each quote keeps the path it came from, which can differ from the row price.

Review a domain's backlink profile

Record the domain form you queried, with or without www and subdomains, and the date of the call. Compare totals only within one provider, and keep the referring domains with the summary so a later call can show what changed.

Candidates today, most buyers first: Citable ($0.1/call, 2 buyers)

Put links next to organic visibility

A growing link profile matters when it moves rankings or traffic. Pull the organic footprint for the same domain and date, and keep both results so a reviewer can see whether the two moved together.

Candidates today, most buyers first: Citable ($0.03/call, 2 buyers)

What the listed providers describe

These notes repeat what each provider documents for its link routes, as read on October 22, 2026. Fields, limits and billing rules are the providers' statements; prices come from the matching endpoint type, never from figures written in a description.

Citable

Citable lists GET /v1/backlinks at $0.1, described as backlink totals and top referring domains for a domain. The description does not say how many referring domains a call returns, whether individual linking URLs, anchor text or follow attributes are included, or how fresh the index is, so read the response schema before building a report on it. For context on the same domain, its overview, ranked-keyword and monthly history routes start at $0.03. The provider states that a 4xx or 5xx response cancels the payment instead of settling it, and its listing names Solana as the payment network.

4 backlink endpoints of 17 · $0.1/call (GET /v1/backlinks) · SOL · uptime 30d 100% · 199 ms · 2 buyers in 30 days

What backlink data costs at volume

The median selected call costs $0.1, so 100,000 calls total $10,000.00 at that rate. The table repeats the calculation for the median, the cheapest specialized service and the providers described above.

Each service at the price of its main backlink endpoint, the one named in the table above.

Backlink work is usually counted in domains and refreshes, not in single calls. Watching 50 competitor domains every week is a little over 200 profile calls a month; adding the organic footprint for each doubles that. A full list that needs several paginated calls per domain multiplies the figure again.

Set the refresh rate by how fast the decision changes. A monthly review of competitors rarely needs daily data, while a cleanup after a site migration may need a few close checks. Keep the route and the date with each charge so the cost can be matched to the reports you kept.

Inspect a backlink request and its payment terms

For a backlink profile, Citable documents GET /v1/backlinks with a reference quote of $0.1. Read its current request schema for the domain format before paying, and check that the response fields match what your report stores.

The listed method and description establish the advertised contract. This explanation does not reproduce an HTTP 402 challenge or certify a paid response. Request the challenge for the exact call you intend to make and compare resource, method, network, asset and amount before authorizing payment. A challenge for a domain-overview route on the same host does not authorize a backlink request.

How this comparison is built

The comparison starts from services that are online and payment-ready, with a known price, a description of at least 80 characters and measured 30-day uptime of at least 90%. The page keeps services whose name or description mentions backlinks. Endpoint selection then reads each service's documented routes, and a service enters the table only with a priced route that returns a backlink profile. Authority scores and organic footprints are classified separately and shown as context; internal-link analyzers and link plans describe links inside one site and stay out.

Descriptions and endpoint lists were read from the public listing on October 22, 2026. Fields and billing rules quoted here are provider claims; x402-list has not compared the delivered links with the live web. Buyer counts are distinct paying wallets over 30 days, and monitoring measures availability and response time of the payment endpoint.

Prices are the reference amounts listed for each endpoint. A route with pagination, tiers or a quote before purchase can cost a different amount for your request, so treat the reference price as a starting point.

Questions

How to pay

Each service answers an unpaid call with HTTP 402 and its price; your agent signs a USDC payment on the listed network and retries. No API key, no account, no subscription. See what x402 is.