9 best backlink APIs for developers in 2026, including cheap Ahrefs API alternatives

For full per-link backlink data with no subscription, the best-value backlink API is DataForSEO: $0.024 per task plus $0.000036 per row. If you already pay for a suite, Ahrefs and Semrush offer the deepest data. The cheapest paid way to get referring-domain lists is backlinks.sh, at $0.004–$0.01 per request. Moz has the only permanent free API plan (50 rows a month). BacklinkMCP gives 10 free domain-level lookups a day with no signup.

What a backlink API returns

A backlink API answers "who links to this site?" in JSON. The full-index providers return link rows: source URL, target URL, anchor text, rel attributes, and first-seen and last-seen dates. They also return aggregates such as referring domains and an authority score. Lighter APIs return only the domain-level graph: which domains link to the target, and how strong each one is. Which kind you need decides the price you pay, so the comparison below separates the two.

If what you want is a single number for a domain, you want an authority API rather than a backlink API. Our domain authority API page covers that call specifically.

How we evaluated

On 2026-10-15 we read each provider's own API docs and pricing page. Every price below is the vendor's own figure unless we say otherwise. Several numbers that circulate in comparison posts (some written by competing vendors) don't appear on the vendor's own page. Where that's the case we name the source or leave the number out. "Not stated" means the vendor's page doesn't say. The criteria were entry price, free path, authority metric, endpoint coverage, and the index size the vendor claims, labelled as a claim.

Disclosure: we build BacklinkMCP, one of the APIs below. It's domain-level only. The table says plainly where the full-index providers do more.

Quick comparison

List prices from vendor pages read on 2026-10-15. Index sizes are each vendor's own claim, and the vendors count differently (links, edges, URLs crawled), so the figures can't be compared directly.

The 9 backlink APIs, reviewed

1. Ahrefs API v3: the reference index

The Ahrefs API is available on "eligible paid plans." Its pricing page lists "API and MCP access" on Lite ($129/mo), Standard ($249) and Advanced ($449). Enterprise ($1,499/mo, billed yearly) has uncapped API use. Requests are billed in API units, with a minimum of 50 units per request. Rows per request are capped at 100, 250 and 500 by plan, and the rate limit is 60 requests a minute. Site Explorer endpoints cover backlinks, referring domains and Domain Rating. Free test queries work only against ahrefs.com, yep.com and firehose.com.

Best for: anyone whose clients already quote Ahrefs DR. Watch for: some comparison posts still say the API is Enterprise-only. Ahrefs' own pricing page now lists it from Lite.

2. Semrush Backlinks API: rich endpoints, unit-priced

Semrush's v4 Backlinks API is in Early Access and billed at v3 rates. It needs a paid plan and a separately bought API units package. Costs are per request or per line: Overview 45 units a request, Backlinks 45 a line, Referring Domains 40 a line, Anchors 40 a line, Pages 40 a line. Endpoints include Overview, Backlinks, Referring Domains, Referring IPs, Anchors, Pages, Competitors and Score Profile, with a 0–100 Authority Score. The docs don't give a dollar price per unit.

Best for: Semrush customers. Watch for: per-line pricing adds up fast on large link lists.

3. DataForSEO Backlinks API: the cheap Ahrefs API alternative

DataForSEO is pay as you go: $0.024 per task plus $0.000036 per row returned. You need a minimum $50 top-up, the funds don't expire, and there's a $1 trial credit and a free playground. Endpoints cover summary, backlinks, history, anchors, referring domains, domain pages, intersection, and bulk lookups of up to 1,000 targets. Its own score, "DataForSEO Rank," is explicitly not 1:1 with Ahrefs DR. Live counters on its page claim roughly 2 trillion live backlinks.

Best for: developers and SaaS builders who want full link rows without a subscription. Watch for: SE Ranking's comparison post says the Backlinks API carries a separate $100 monthly minimum. DataForSEO's backlinks and pricing pages don't mention one, so confirm before you budget.

4. Moz Links API: the only permanent free tier

Moz's free API plan gives 50 rows a month at one request per 10 seconds. Starter is $20/mo for 3,000 rows or $75/mo for 15,000 rows, with overage at $5 per 1,000 rows. Growth runs $125–500/mo for 50,000 rows. The data includes links plus Domain Authority, Page Authority, Spam Score and Brand Authority. Moz claims 45.5 trillion links across 1 billion domains, though other pages on its site say 44 or 40 trillion.

Best for: small tools that need DA on a budget. Watch for: row-based billing. Pulling a long link list for one domain uses rows quickly.

5. Majestic API: Trust Flow and a deep history

Majestic issues API keys to "Platinum or API subscribers." The API page shows no price, and the $49.99 Lite plan is Site Explorer only. Commands include GetIndexItemInfo, GetBackLinkData, GetRefDomains, GetNewLostBackLinks and GetAnchorText, and there's a free sandbox with a small test database. On 2026-10-15 its page reported 188.6 billion unique URLs crawled in the Fresh index and 4.5 trillion in Historic (2006 to March 2024).

Best for: link-history research and Trust Flow reporting. Watch for: price discovery means contacting sales or reading third-party posts.

6. SE Ranking API: credits or add-on

SE Ranking sells a stand-alone pay-as-you-go API from $50 per 250K credits. It also sells an API add-on from $149/mo. The same page says the API is included in the Core ($129) and Growth ($279) plans, and that inconsistency is on the vendor's own page. Endpoints cover backlink summary, the full list, new and lost links, anchors, referring domains, referring IPs and subnets, and page and domain authority with history. There's a free trial with no card.

Best for: teams already in SE Ranking. Watch for: confirm which billing path your account is on.

7. backlinks.sh: cheapest referring-domain lists

backlinks.sh uses credits with no subscription, one credit per request, and credits don't expire. $10 buys 1,000 credits ($0.01 a request) and $400 buys 100,000 ($0.004 a request). One call returns up to 10,000 referring domains, ranked by authority and paginated 1,000 to a page. Each domain carries ranks from Majestic, Tranco and OpenPageRank. It's built on the Common Crawl web graph, which it says holds 10.9B edges across 250M domains. It doesn't offer an MCP server.

Best for: bulk referring-domain pulls at the lowest unit cost. Watch for: it returns domains, not individual links or anchors.

8. RankParse: per-lookup, own index

RankParse charges from $0.01 a lookup with no subscription. Credits don't expire, and new accounts get 100 free credits. Backlinks come from its own Common Crawl-based index, which it says holds 28B+ backlinks. It also offers an MCP connector. Its homepage doesn't list the response fields.

9. BacklinkMCP: free domain-level API for agents and scripts

BacklinkMCP (ours) serves the same engine over REST and MCP. GET /api/v1/authority?domain= returns domain_rating, referring domains and outbound links. GET /api/v1/backlinks?domain= returns the ranked referring-domain list. Free use is 10 lookups a day per IP with no signup, and up to 25 backlink rows. Pro is $19/mo for unlimited daily lookups and up to 100 rows. Self-serve checkout isn't live, so Pro keys are issued on request. You can try a lookup in the browser with the free backlink checker.

Best for: agents and prototypes that need "who links here and how strong is it" without an account. Where others win: it's domain-level. There are no per-link source URLs, no anchor text and no rel/dofollow state, and the free tier's row cap is small. Use DataForSEO, Ahrefs, Semrush or Majestic for link-level audits. The Ahrefs alternative page covers the trade-off in detail.

Worked example: referring domains for 100 sites

Say you want the top 1,000 referring domains for each of 100 domains, using vendor list prices:

These are list prices only. DataForSEO's page shows its own 1,000-row example as $0.05, while the arithmetic gives $0.06. Run one real call against your own targets before you budget.

Which backlink API pages AI assistants cite (our test)

We ran five developer questions (best backlink API, cheap Ahrefs API alternative, best SEO MCP server, giving an agent backlink data, and checking authority via API) through Perplexity Sonar and Gemini with web search, three times each. That's 30 answers, and we counted every URL they cited. The most cited were SE Ranking's "Ahrefs API alternatives" post, Semrush's Backlinks API docs and DataForSEO's Backlinks API page (9 citations each), Keyword.com's MCP roundup (8), then backlinks.sh and Majestic's API page (6 each). Our own homepage was cited 3 times, all by Gemini on the agent question. The pattern is clear: assistants cite vendor docs pages with explicit prices and endpoints, and comparison posts that carry a table. This page follows that format.

How to choose

• You need anchors, URLs and history for audits: DataForSEO if you want pay as you go, or Ahrefs or Semrush if you're already subscribed.
• You need a familiar score for clients: Moz (DA), Ahrefs (DR) or Majestic (Trust Flow).
• You need lots of referring-domain lists cheaply: backlinks.sh.
• You're prototyping or wiring an agent and want zero setup: BacklinkMCP. If the agent should call it as a tool, see Best MCP servers for SEO.

Sources

Vendor pages read on 2026-10-15 (plain text, not links):

• Ahrefs: docs.ahrefs.com/en/api/docs/introduction · docs.ahrefs.com/en/api/docs/free-test-queries · ahrefs.com/pricing
• Semrush: developer.semrush.com/api/v4/seo/backlinks/ · developer.semrush.com/api/basics/introduction/
• DataForSEO: dataforseo.com/apis/backlinks-api · dataforseo.com/pricing
• Moz: moz.com/products/api · moz.com/products/api/pricing
• Majestic: majestic.com/account/api
• SE Ranking: seranking.com/api.html
• backlinks.sh: backlinks.sh
• RankParse: rankparse.com
• Roundup cited for the unconfirmed DataForSEO minimum: seranking.com/blog/ahrefs-api-alternatives/

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