Seonio Launches SEO API for Keywords, Traffic, Rankings and Authority Data

Seonio is expanding from an SEO research platform into a developer-friendly SEO data layer.

We are launching the Seonio SEO API, a simple JSON API that lets teams build keyword metrics, organic traffic data, ranking intelligence and authority metrics directly into their products, dashboards, internal tools and automated workflows.

The new API is designed for developers, agencies, SaaS teams and growth teams that need SEO data without complicated pricing models or heavy integration work.

Why we built the Seonio API

SEO data is also useful outside an SEO tool. Product teams want to show keyword opportunities inside customer dashboards. Agencies want to automate client reporting. Growth teams want to qualify domains and pages at scale. Developers want clean data that can be integrated into their own workflows without manual exports.

The Seonio API was built for exactly that. With a few POST requests, teams can query the SEO data they need and use it inside their own applications.

What is included

The Seonio API includes five endpoints:

Each endpoint includes documentation, request examples, sample responses and a playground so developers can inspect the API before integrating it.

Example API request

Here is an example request to the Keyword Research API.

curl -X POST https://seonio.com/api/v1/keywords/global \
  -H "Content-Type: application/json" \
  -H "X-API-Key: $SEONIO_API_KEY" \
  -d '{"keywords": ["keyword research", "seo tools", "domain authority checker"]}'

Example response:

{
  "keywords": [
    {
      "text": "keyword research",
      "volume": 550000,
      "cpc": 37,
      "competition": 1,
      "trend": [
        18100,
        27100,
        27100,
        201000,
        450000,
        49500,
        673000,
        1830000,
        2740000,
        1000000,
        40500,
        22200
      ]
    }
  ]
}

The same pattern applies across the API: send JSON, authenticate with your API key and receive structured JSON back.

Keyword data for research tools and content workflows

The Keyword Research API returns volume, CPC, competition and a 12-month trend for up to 100 keywords in one call.

This makes it useful for:

• Keyword research dashboards

• Content planning tools

• Bulk keyword analysis

• SEO and PPC opportunity scoring

• Content brief automation

• Backlog prioritization based on demand and competition

Instead of manually collecting keyword metrics, teams can build keyword intelligence directly into their own workflows.

Organic traffic history for competitor monitoring

The Website Traffic API returns monthly organic traffic history for a domain.

This endpoint is useful when your product or workflow needs to understand traffic trends over time. For example, you can use it to build competitor tracking dashboards, detect growth or decline patterns, qualify leads by estimated organic reach or power domain overview pages.

A simple request body looks like this:

{
  "domain_name": "moz.com"
}

The response includes the domain name and an organic_monthly array with monthly traffic values from oldest to newest.

Ranking intelligence for domain analysis

The Website Ranking API provides a broader view of how a domain performs in search.

It returns data such as:

• Total ranking volume

• Estimated traffic value

• Top country

• Country distribution

• Keyword position distribution

• New, rising, falling and lost keyword counts

• Top keywords

• Top pages

This endpoint is designed for competitor analysis screens, domain overview reports, opportunity discovery tools and SEO monitoring workflows.

For example, a product could use this endpoint to show which pages drive the most ranking value for a domain, which countries matter most and whether the domain is gaining or losing visibility.

URL and domain authority metrics

The API also includes two authority-focused endpoints.

The URL Stats API returns page-level and domain-level authority metrics for a specific URL. This includes page authority, domain authority, spam score, linking domains, linking pages and nofollow pages.

The Website Stats API returns authority metrics for a bare domain. It uses the same response shape as URL Stats, but focuses on the domain instead of a specific page.

These endpoints are useful for:

• Backlink qualification

• Link prospect scoring

• SERP analysis tools

• Authority badges

• Landing page evaluation

• Domain comparison features

• Internal lead scoring systems

Built for predictable production workflows

The Seonio API is intentionally simple to work with.

Every endpoint accepts JSON via POST requests. Authentication is handled through an API key. Request bodies and response fields are documented clearly on each endpoint page.

The API also uses predictable status codes:

This makes it easier to build reliable integrations, monitor failures and handle errors in production.

Fixed dollar pricing instead of credit math

A major goal of the Seonio API is pricing clarity.

Many APIs use abstract credits that make it hard to understand what a request actually costs. Seonio uses fixed dollar pricing instead.

You add funds to your API balance, then requests are charged directly against that balance. There is no credit conversion to calculate.

API balance does not expire. New accounts also start with $1 in free API balance, so developers can test the API before topping up.

Available balance options include:

Coverage across 50 markets

The Seonio API currently supports 50 markets.

This makes it useful for products and workflows that need international SEO data, multi-market research or country-level opportunity analysis.

Supported markets include the United States, United Kingdom, Germany, France, Spain, Canada, Australia, India, Brazil, Japan, Singapore, United Arab Emirates and many more.

What developers can build with the Seonio API

The API can power many SEO and marketing data use cases, including:

• Keyword research products

• Content planning dashboards

• Competitor monitoring tools

• Domain overview reports

• Backlink qualification workflows

• Lead scoring systems

• Agency reporting automation

• Internal growth dashboards

• SEO alerting and monitoring tools

• SERP and landing page analysis products

Because the API returns structured JSON, it can be used in SaaS products, scripts, data pipelines, dashboards and internal tools.

Start building with the Seonio API

The Seonio API is available now, You can explore the API overview here:

https://seonio.com/product/api

Endpoint documentation and playgrounds are available here:

• Keyword Research API

• Website Traffic API

• Website Ranking API

• URL Stats API

• Website Stats API

New users can create a free account, receive $1 in free API balance and start testing the API without a credit card.

With keyword metrics, traffic history, ranking intelligence and authority data available through a simple JSON API, Seonio gives developers a faster way to build SEO data into the products and workflows they already use.