I Built a Free Text Analysis API -- Readability, SEO & Sentiment in One Call

I kept running into the same problem across different projects: I needed to analyze text content programmatically -- readability scores, keyword density, sentiment -- and every solution was either expensive, slow, or required wrangling an LLM for something that should be deterministic. So I built TextOptimizer, a lightweight REST API that gives you readability metrics, SEO analysis, and sentiment scoring in a single POST request. No AI models, no per-token billing, no waiting 3 seconds for a response. Just algorithms, math, and sub-100ms response times. Here is what it looks like in practice. The API in 30 Seconds One endpoint. One request body. Three categories of analysis back. curl -X POST https://textoptimizer-api.vercel.app/analyze \ -H "Content-Type: application/json" \ -H "X-API-Key: YOUR_API_KEY" \ -d '{ "text": "Artificial intelligence is transforming how businesses operate. Companies that adopt AI early gain a significant competitive advantage in their markets. The technology