API guide

We have a full, detailed reference for API v3 here: Ahrefs API documentation. This page is a brief introduction for Ahrefs Connect developers.

What you can do with API v3

Ahrefs API v3 lets you pull a wide range of data, including:

Organic and backlinks data from Site Explorer (for your site or competitors)
Keyword metrics and ideas from Keywords Explorer
Google SERP data
Data from the user’s Rank Tracker and Site Audit projects
And more — we regularly add new endpoints

API units and request costs

All requests — except for free test queries and Rank Tracker, Management, Public, and a few other endpoints — consume API units from the connected user’s account.

Cost rules:

Depends on the number of rows returned and the fields requested
Minimum cost for any paid request: 50 units
If an endpoint is free, it’s marked as such in its documentation page

During development

As explained in How it works, when your app is first created, it will be in Inactive status. In this mode, you can test OAuth flows and send free test requests to API v3 endpoints from your staging setup without consuming units. Once your app is approved and activated, production requests will consume units according to the normal cost rules.

info

Best practices to save user API units

When making requests on behalf of users, be mindful of their monthly allowance.

Here’s how to minimize unit consumption:

Use select to request only needed fields: most endpoints let you specify fields.
Limit the number of rows: use limit or equivalent parameters. Avoid pulling thousands of rows unless necessary.
Use bulk endpoints where possible: for example, batch-analysis lets you pull metrics for many pages in one request.
Let users monitor their usage: the limits-and-usage endpoint shows how many units they have left.