Ahrefs vs Semrush vs Moz vs SpyFu API Pricing (2026): What Domain and Keyword-Gap Data Actually Costs

Who actually needs this comparison

"How much does the Ahrefs API cost" and "Semrush API pricing" both get thousands of searches because the answer is genuinely hard to find — API access is buried inside subscription tiers, priced in opaque "units" or "credits" that vary by report, or not published at all. If you're building a keyword-gap tool, a domain-research feature, or an agency reporting pipeline, you need the real number before you commit a subscription, not after.

This is that number, for five vendors, read off each vendor's own page where a page would load, dated 2026-09-13. Where a vendor doesn't publish a figure, the table says so instead of estimating one.

The pricing, vendor by vendor

Sources: ahrefs.com/pricing, developer.semrush.com, developer.spyfu.com/docs/api-pricing — all fetched directly, 2026-09-13. Moz and Similarweb rows are third-party-sourced this round; re-verify before treating either as settled.

Why "per unit" doesn't mean "per dollar" here

Every vendor above except SpyFu and Searlo prices its API in an internal currency — "credits" or "units" — with no published dollar-per-unit rate. That's not an oversight on our part: Semrush's own developer docs state a report costs 10 or 50 units without ever pricing a unit in dollars, and Ahrefs' credits are a plan-included allotment with no published overage rate at all. A vendor that will not tell you the dollar cost of one call is not being cagey by accident — it means the plan, not the call, is the product.

SpyFu and Searlo are the two vendors in this set that publish an actual per-row or per-credit dollar rate, which is why they're the only two rows above with a real "unit cost" column instead of "bundled into the plan."

What a 10-competitor keyword-gap pull costs, where it's computable

Take one concrete workload: pull the keyword gap between your domain and 10 competitors, unverified (no live position checks, just the association data).

• Searlo: 2 credits per domain in the comparison (1 target + 10 competitors) = 22 credits, or about $0.0066 at the $0.30-per-1,000-credit rate — a fraction of a cent, from a one-time pack, no plan required.

• SpyFu: Competitors report is $0.20 per 1,000 rows — cheap per row, but only reachable behind the $119/mo Pro+AI plan (or $249/mo Team/Agency), which is the real floor for this workload.

• Ahrefs: not computable at any price. Content Gap is a Site Explorer dashboard-only tool — it has no API endpoint at all, at any subscription tier, so there is no per-gap cost to quote.

• Semrush: not computable. The Organic Keywords report costs 10-50 units/line, but with no published dollar-per-unit rate, "how much did this gap pull cost" has no answer you can get from Semrush's own site.

• Moz, Similarweb: neither publishes a comparable content-gap product at this price point — Similarweb's offering here is an enterprise add-on, not a metered API call.

The pattern holds beyond this one workload: whenever a vendor publishes a real per-unit dollar rate, the arithmetic is simple. Whenever a vendor prices in "credits" or "units" without a dollar conversion, the honest answer is that the number doesn't exist yet — you'd have to sign up and ask.

Per-vendor notes

Ahrefs — the widest bundled tiers, no metered option

Ahrefs' Site Explorer API is the closest one-to-one match to a "domain SEO API" product category on the reports it does expose — Overview, Organic Keywords, Organic Competitors and Top Pages — and the pricing is the simplest to state precisely because it's entirely tier-based: no API on the $29/mo Starter plan, API and MCP access from Lite ($129/mo, 1,000 credits/user), unlimited credits per user from Standard ($249/mo), and an uncapped Enterprise tier at $1,499/mo on an annual commitment. Content Gap, notably, is not one of them — it's a Site Explorer dashboard-only tool with no API endpoint at any tier (confirmed against Ahrefs' own API reference), so a keyword-gap workload specifically has no Ahrefs-API path at all, bundled or otherwise. If your team already has an Ahrefs seat for the dashboard, API access to the four reports it does expose is effectively free at the margin; if you don't, $129/mo is the entry cost regardless of call volume.

Semrush — a unit count with no dollar attached

Semrush's own developer documentation is specific about API unit consumption — the Organic Keywords report costs 10 units per line for live data, 50 for historical — which is more transparent than Ahrefs on mechanism. It is completely opaque on price: nowhere on Semrush's own site could we find a dollar figure for what a unit costs, or a unit allotment tied to a specific dollar plan. Third-party trackers report an Advanced-plan floor of $549/mo ($455.67/mo billed annually) as the cheapest plan bundling API access, but that figure is not confirmed on a Semrush vendor page this session, so treat it as reported, not verified.

SpyFu — the closest structural analogue to a per-call API

SpyFu is the only vendor in this comparison, besides Searlo, whose API pricing is a straightforward per-row rate: $0.50 CPM for Domain Stats and most keyword endpoints, $5.00 CPM for Top Pages, $0.20 CPM for Competitors. That's real pay-per-row pricing, the same shape this whole comparison is trying to find. The catch is the floor: none of those rates are reachable without a Pro+AI ($119/mo) or Team/Agency ($249/mo) subscription that includes a monthly API credit allowance — so even SpyFu's metered model requires a $119+/month commitment before the per-row math starts.

Moz — likely the cheapest link-only tier, unverified this round

Third-party trackers describe a standalone Moz API product starting around $49/mo for Level 1 access (Domain Authority, Page Authority, and link data) with a free tier around 50 rows/month, separate from the $49-$299/mo Moz Pro dashboard subscription. moz.com/products/api did not return usable content when we tried to fetch it directly this session, so none of those figures are vendor-confirmed here — if Moz pricing matters to your decision, check moz.com directly before relying on this row.

Similarweb — not a metered API at all

Similarweb doesn't sell what the rest of this table sells. There is no self-serve pricing page, no published per-call rate, and no free tier; third-party sources consistently describe it as a custom-quoted, credit-consumption add-on layered on top of an Enterprise seat, with reported module pricing in the $20,000-$60,000+/year range. That's directionally consistent across multiple secondary sources but not something we could confirm on similarweb.com/corp/api/ directly. If your workload is "call an endpoint, get keyword data back," Similarweb is likely the wrong shape of vendor regardless of budget.

The market already has a pay-per-call precedent

None of this is a new idea. DataForSEO's Domain Analytics API — a different product from the five compared above, covering Whois and Technologies lookups rather than keyword/gap reports — prices at $0.012 per task and $0.0012 per item for Technologies data, no subscription required. It's not a head-to-head competitor for keyword-gap or competitor-overlap reporting, but it confirms the market already accepts metered, no-subscription pricing for domain-level data; the five vendors above choosing tier-bundling instead is a business decision, not something the underlying data requires.

Methodology and what we could not verify

What we did: fetched each vendor's own pricing or developer-docs page directly on 2026-09-13 and recorded the figures as published, including unit counts and dollar amounts where a vendor stated them.

What we did not do: invent a dollar-per-unit rate where a vendor didn't publish one. Semrush's unit cost, Moz's API pricing, and Similarweb's module pricing all fall into that gap — reported by third parties, not confirmed on the vendor's own page this session. Anywhere this post states a Moz or Similarweb figure, treat it as indicative rather than settled, and re-check the vendor's page before making a purchasing decision on it.

Which to pick

• Want the dashboard and the API bundled, and you're already paying for Ahrefs — API access to Ahrefs' four exposed reports is effectively free at the margin once you're on Lite or above; just mind the 1,000-credit/user cap below Standard, and note Content Gap isn't part of the API at any tier.

• Want a real per-row metered rate and can absorb a $119+/mo floor — SpyFu is the closest match to a conventional pay-per-use API in this set.

• Want metered pricing with no subscription at all — that's the gap none of the five subscription-first vendors fill; see our domain SEO API and Ahrefs API alternative pages for the per-call version of these same report types, including a keyword-gap report Ahrefs doesn't sell via API.

• Need backlink profiles, Domain Rating, or a multi-year link history — that data lives in Ahrefs' and Semrush's crawled indexes specifically; no per-call API, ours included, replicates it.