OpenAI vs Anthropic: which API should I use?

Both APIs are production-ready for business applications. The choice depends on your specific use case, safety requirements, and cost sensitivity.

OpenAI (GPT-4o, GPT-4o-mini): Largest ecosystem and community. More third-party integrations. Broader model range (text, image, audio, video). Better for: multimodal applications, function calling with complex tool chains, and projects where ecosystem/community support matters.

Anthropic (Claude Opus, Sonnet, Haiku): Better at following complex instructions and long-form writing. Larger context window (200K tokens vs 128K). Stronger safety features and more predictable behavior. Better for: RAG applications (large context), customer-facing applications (safety), document analysis (long-form processing), and nuanced writing tasks.

Cost comparison (as of 2026): GPT-4o: $2.50/$10 per million input/output tokens. Claude Sonnet: $3/$15 per million tokens. GPT-4o-mini: $0.15/$0.60. Claude Haiku: $0.25/$1.25. For high-volume applications, the cost difference matters — run benchmarks on YOUR specific tasks, not generic benchmarks.

Practical recommendation: for most B2B applications, start with Claude Sonnet or GPT-4o for complex tasks, and Claude Haiku or GPT-4o-mini for high-volume simple tasks. Don't commit to one provider — build an abstraction layer that lets you switch models based on task requirements.

Vendor lock-in risk: both APIs are similar enough that switching costs are low. The bigger lock-in is in fine-tuned models, which aren't portable between providers.