Ad text for Google, Facebook and Instagram written to lift CTR and cut CPC.
How to get a free Marketing & SEO API key
Four steps from a blank editor to a working call, across the 11 Marketing & SEO APIs in this catalogue — all on a plan that costs nothing.
The steps
-
Compare the options
This catalogue has 11 Marketing & SEO APIs with a free plan. Sort them by endpoint count, latency or subscribers and shortlist two or three that cover what you need.
-
Open the listing and subscribe to the free plan
Every listing links straight to the marketplace page. AI ad copy generator — Google & Meta Ads API is the most subscribed one in this category, which makes it a safe first stop. The Basic plan costs $0 and asks for no card.
-
Copy your API key
The key appears the moment the subscription is created. It goes in a request header — never in front-end code or a public repository.
-
Make the first call and check the quota
The marketplace playground runs a real request in the browser before you write any code. Once it answers, watch the monthly quota: the free tier is generous but not unlimited, and every Marketing & SEO listing publishes its own limit.
Which Marketing & SEO API to start with
Detect AI-generated text and rewrite it to read naturally.
Score any text for quality, relevance, grammar, originality, readability and SEO.
Meta descriptions, headlines and keyword sets generated together.
Guidance on SEO, social, content, email and paid campaigns on demand.
SEO-ready product copy in many languages for Shopify, Amazon, Etsy and more.
Frequently asked questions
- How many free Marketing & SEO APIs are listed here?
- This catalogue lists 11 Marketing & SEO APIs, all with a plan that costs $0. The most used are AI ad copy generator — Google & Meta Ads API, AI content detection & text humaniser, AI content quality & topic relevance checker.
- Which free Marketing & SEO API covers the most endpoints?
- AI ad copy generator — Google & Meta Ads API covers the most ground with 3 endpoints.
- What does the cheapest paid Marketing & SEO plan cost?
- Past the free plan, AI ad copy generator — Google & Meta Ads API is the cheapest at $9.99 a month.
- Are these Marketing & SEO APIs really free?
- Yes. Every Marketing & SEO API listed here has a plan that costs $0 a month and needs no card. Paid plans exist for higher volume and their prices are in the table above.