Ahrefs API vs Semrush API: Pricing, Limits and Fit

Choose Ahrefs when its backlink index, Domain Rating or historical continuity is the requirement. Choose Semrush when its competitor keyword reports, domain analytics or separately licensed traffic intelligence are the requirement. For either vendor, price the exact API workload after confirming subscription eligibility. A suite's headline price is not a per-call quote.

Pricing reference: 17 October 2026. Vendor prices, access terms and usage rates below are previously recorded reference values, not freshly verified current offers. Confirm current access, endpoint rates and unit prices with Ahrefs and Semrush before purchasing. This is a documentation-based comparison with illustrative calculations, not a hands-on coverage or speed benchmark.

This article compares the two vendors' direct APIs. Their MCP routes appear separately because connector access can have different entitlements. For the full standalone cost models, see Ahrefs API pricing and Semrush API pricing.

Decide which dataset must survive the choice

This matrix establishes documented categories, not equal report coverage. “Keywords” might mean keyword volume, competitor rankings or your own site's Search Console queries. Write down the required output before deciding that two similarly named endpoints answer the same question.

Neither provider's index-update cadence guarantees discovery of a particular backlink by a deadline. If a placement must be verified today, add a direct check of that page rather than treating an index's absence as proof the link does not exist.

Subscription access and unit models

Sources: Ahrefs pricing, Ahrefs subscription-plan help, Ahrefs API docs, Semrush API access, Semrush developer docs and Semrush pricing, using the dated pricing reference above. Prices are USD.

Two mistakes make this table easy to misread. First, Ahrefs Connect integration units are not an established direct API allowance. Second, Semrush's cheapest general SEO subscription is not a confirmed Standard API entry plan. Leave either value unresolved until your account or quote confirms it.

Two matched workloads, with explicit unknowns

Use the same 100 domains for both workloads. Assume successful calls, no retries and sufficient source data. The output target is comparable; matching request sizes does not make the returned scores or links equivalent. The calculations below are conditional arithmetic using the previously recorded reference rates; they were not executed against either vendor.

Workload 1: one authority signal per domain

For Ahrefs, model 100 individual Domain Rating requests, each with a total field cost below the 50-unit minimum. A vendor-specific batch endpoint could change the call pattern and must be budgeted separately.

The Semrush backlink rate does not belong in the Authority Score row. Nor does the live organic-keyword report's 10-unit rate establish a universal price for a domain score. An honest worksheet leaves an unsupported rate blank and asks for the right report.

If your goal is a new generic enrichment signal, also assess whether either proprietary metric is necessary. If your client contract specifies DR or Authority Score, using another vendor changes the deliverable.

Workload 2: up to 1,000 backlink rows per domain

The target is 100,000 URL-level rows, with enough information to identify source URL, target URL and anchor. For Ahrefs, model a total of five 1-unit billable fields per row, including any charged filter and sort fields. For Semrush, use the recorded backlink report rates only if they apply to the chosen route.

For Ahrefs, each full slice exceeds the 50-unit minimum, so larger row caps reduce requests without changing this particular row-and-field total. Expensive fields, additional filters and partially filled requests can change it.

The multi-request capacity figures assume the endpoint supports distinct result slices. They are not a verified pagination recipe or a guarantee that the complete target can be exported. Before implementation, confirm limits and continuation for the actual endpoint; repeatedly fetching the same capped output does not expand coverage.

The unit totals cannot be ranked as dollars. One Ahrefs unit is not one Semrush unit. We do not have a comparable current dollar-per-unit quote or confirmed usable allowance for both. The right next step is to apply each vendor's own quote to its modeled usage.

Convert the worksheet into a cash budget

For a new customer, include the eligible subscription and any required unit package. For an existing customer, count the remaining uncommitted allowance before assigning an extra purchase. Record the package actually bought, since it may be larger than this job's usage.

job usage = sum(billable units across all requests)
extra units needed = max(0, job usage - usable remaining allowance)
new cash outlay = newly required subscription + required unit-package purchase

Treat the subscription as already paid only when you would retain it independently of this job. If this pipeline is the reason for the purchase, its fixed access cost belongs in the comparison.

Request, authentication and response differences

A move between the APIs requires an adapter and data validation, not just a new base URL. Normalize domains and URL scope, map fields, preserve null values and update the parser. Check whether filters refer to links, referring domains, live status or another vendor-specific definition.

If you must retain a legacy query-key API, redact query strings from logs and monitoring. For header-token routes, keep tokens in environment variables and out of recorded request examples.

Do not carry authority thresholds across vendors without recalibration. Similarly, a change in a domain's reported backlink count after migration could reflect coverage or aggregation differences rather than a real-world gain or loss. Store the provider and data date alongside the result so downstream users can interpret it.

MCP changes the connection, not the data requirement

Confirm current MCP eligibility, row caps, included usage and renewal separately from direct API access in Ahrefs pricing and Semrush's developer documentation. Do not assume direct API, integration and MCP allowances are interchangeable.

Check which tools can spend each account balance and whether Trends traffic tools require separate data access. If the task is primarily conversational, compare available tools first, then budget the calls the agent may make. AI client and model costs can sit alongside provider usage.

The SEO MCP comparison covers tools and clients; SEO MCP pricing explains access, data usage and model bills.

When neither suite is needed

If the requirement is a bounded backlink sample or a new domain-enrichment signal, a narrower API may fit. RankParse offers 100 introductory credits, then prepaid usage with no subscription and credits that never expire. An authority lookup is 1 credit; ordinary backlinks are 2, or 3 with scoring.

The same 100-domain backlink target would use 200 credits, a $2 value at the base rate, using one limit=1000, sort=recent call per domain with scoring off. With an unused welcome balance, 100 additional credits are needed. A $10/1,000-credit example purchase leaves 900 credits after the job when the welcome balance is applied. This is purchase arithmetic, not a measured vendor savings figure.

RankParse serves a periodic link-graph snapshot from quarterly public-web releases. Check the active dataset date rather than assuming a current-quarter release. It does not supply Ahrefs DR, Semrush Authority Score, either suite's competitor keyword database or a matching historical link series. Its backlink endpoint has no offset pagination beyond the 1,000-row ceiling. Equal requested limits do not establish equal output coverage.

For a supported workload, see RankParse vs Ahrefs, RankParse vs Semrush and the backlinks response contract.

FAQ

Is Ahrefs API cheaper than Semrush API?

The access and usage models differ, and a current comparable unit quote is required. Ahrefs' recorded $129/month Lite reference is a dated subscription figure, not a current quote or the total price of a high-row job. Semrush's eligible subscription and separate package need a current quote. Unit counts alone cannot decide which is cheaper.

Which API has better backlink data?

This article does not include a measured coverage study. Evaluate the same representative domains, scope, fields and date requirements. If you need Ahrefs DR or Semrush Authority Score, that metric requirement may decide the provider before row counts do.

Can I use one vendor for keywords and another for backlinks?

Yes, if licensing and your application permit it. Keep data provenance, metric definitions and usage budgets separate. Multiple providers also add integration and maintenance work, so compare the operational cost with any usage savings.

Does MCP remove the paid-plan requirement?

Check each vendor's MCP entitlement. Confirm any included allowance and paid-plan requirements with the provider. A free client connection or an included allowance does not imply unrestricted free data or equivalent direct API access.

What to build next

Choose the non-negotiable dataset and fields, then run a small bounded sample before committing a larger budget. Use the Ahrefs pricing worksheet or Semrush pricing worksheet to fill in account-specific allowances and quotes. If a periodic snapshot fits a narrower task, review RankParse backlinks and pricing before trying it.