Ad text for Google, Facebook and Instagram written to lift CTR and cut CPC.
Best free Marketing & SEO APIs
11 Marketing & SEO APIs with a free plan, compared side by side on endpoints, latency and price.
Which one to pick
- AI ad copy generator — Google & Meta Ads API covers the most ground with 3 endpoints.
- AI ad copy generator — Google & Meta Ads API was updated most recently, on 2025-11-26.
- Past the free plan, AI ad copy generator — Google & Meta Ads API is the cheapest at $9.99 a month.
Choosing between APIs in the same category usually comes down to four numbers: how much surface the API covers, how fast it answers, how reliably it stays up and what it costs once the free tier runs out. The table below puts those numbers next to each other so the comparison takes a minute rather than an afternoon of tab-switching.
Every service listed here has a plan that costs nothing and needs no card, so the shortlist can be tested before any of it is paid for.
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.
Best free Marketing & SEO APIs
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.
Keyword-rich articles and web copy written to improve search visibility.
Score a site on usability, accessibility, navigation and performance.
High-quality product descriptions written for search and for conversion.
Full-site SEO audit with performance metrics and actionable fixes.
Tags and hashtags suggested for reach rather than description.