- **Free Tier:** No meaningful free tier; pay-as-you-go. - **Quality:** **Top-notch**, can extract keywords using prompts (but not a specific “extract keywords” endpoint). - **Underlying Tech:** GPT-4o, Transformer models. - **Stability & Support:** **Very high**, but cost can increase unpredictably, and API access rules occasionally shift. - **Cons:** Pricing; “black box”; not purpose-built for keywords (you prompt for it).