OpenAI API vs Anthropic API: Pricing and Structure Compared
Both are frontier API providers with cached-input and batch discounts. OpenAI's gpt-5.5 outputs at $30/1M; Anthropic's Claude Opus 4.8 outputs at $25/1M, and Sonnet 4.6 at $15/1M offers strong mid-tier value. Choose by model fit and cache economics, not headline price alone.
Choose the OpenAI API for the gpt-5.5 family, Flex/Batch modes, and the broadest tooling ecosystem.
Choose the Anthropic API for Claude's reasoning and coding, granular cache-read/write tiers, and a strong Sonnet mid-tier.
Side by side
| OpenAI API | Anthropic API | |
|---|---|---|
| Flagship input | gpt-5.5 — $5.00/1M | Opus 4.8 — $5.00/1M |
| Flagship output | gpt-5.5 — $30.00/1M | Opus 4.8 — $25.00/1M |
| Cached input | $0.50/1M | $0.50/1M (read) |
| Mid-tier | gpt-5.4-mini — $0.75/$4.50 | Sonnet 4.6 — $3.00/$15.00 |
| Context | 1M | 1M |
| Batch | Batch/Flex −50% style | Batch −50% |
OpenAI and Anthropic both price per million tokens with separate input, cached-input, and output rates, plus batch discounts. At the flagship level, gpt-5.5 and Claude Opus 4.8 share a $5.00/1M input price, but Opus outputs slightly cheaper ($25 vs $30).
Mid-tier is where the choice gets interesting. OpenAI's gpt-5.4-mini is very cheap at $0.75/$4.50, while Anthropic's Sonnet 4.6 ($3.00/$15.00) is positioned as a balanced production workhorse with a 1M context window. Anthropic also exposes explicit 5-minute and 1-hour cache-write tiers, which matter for long-running agents.
Because both offer cached input and batch modes, your effective cost depends heavily on cache-hit rate and output length. Model the workload, not just the sticker price.
FAQ
Is OpenAI or Anthropic cheaper?
Do both support prompt caching?
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