OpenAI API Pricing (May 2026)

OpenAI remains the largest AI API provider in 2026, with a pricing ladder that now runs from GPT-4.1 nano at $0.10 per million input tokens to GPT-5.5 Pro at $30.00 per million input tokens. That spread gives teams room to route cheap classification, standard generation, and frontier reasoning inside one vendor stack.

The biggest OpenAI pricing story right now is the launch of the GPT-5.5 family. GPT-5.5 doubles GPT-5.4's flagship rate to $5/$30, but it also jumps to a 1,050,000-token context window and positions itself explicitly for coding, research, and high-value professional work.

GPT-5.5 Family

The new GPT-5.5 lineup covers two premium tiers:

• GPT-5.5 ($5.00 input / $30.00 output, $0.50 cached input) — new flagship for complex professional work, coding, and long-context agents.
• GPT-5.5 Pro ($30.00 input / $180.00 output) — highest-precision variant for expensive-but-important workloads. No cached-input discount.

GPT-5.4 Family

GPT-5.4 remains live as the cheaper mainstream frontier family:

• GPT-5.4 ($2.50 input / $15.00 output) — strong general-purpose frontier model at half the price of GPT-5.5.
• GPT-5.4 mini ($0.75 input / $4.50 output) — still one of the best price/performance picks for production apps.
• GPT-5.4 nano ($0.20 input / $1.25 output) — budget option for routing, extraction, and high-volume backend tasks.

o-Series Reasoning Models

OpenAI's reasoning models use internal "thinking tokens" that increase actual costs beyond the listed per-token rates. The o3 model ($2.00/M input) replaced the expensive o1 ($15.00/M) as the primary reasoning model — an 87% price cut with improved performance.

o4-mini at $1.10/M input tokens offers the most cost-effective reasoning capability in OpenAI's lineup.

GPT-4.1 Family

The GPT-4.1 family still matters for developers who want a 1M-token context window at lower cost than GPT-5.5:

• GPT-4.1 ($2.00 input / $8.00 output) — 1M context, strong for long-document processing
• GPT-4.1 mini ($0.40 input / $1.60 output) — Best value for large context needs
• GPT-4.1 nano ($0.10 input / $0.40 output) — Cheapest model in OpenAI's lineup

Cached Input Pricing

GPT-5.5, GPT-5.4, and GPT-4.1 all support prompt caching on their standard tiers, which can cut repeated-input costs by 75-90%. For example, GPT-5.5's cached input rate is $0.50/M and GPT-5.4's is just $0.25/M — a major lever for agent workflows with big repeated prefixes.

How OpenAI Compares

OpenAI now covers more price bands than Anthropic, but not always at the cheapest rate. GPT-5.5 sits above Claude Opus 4.7 on output cost, while GPT-5.4 mini ($0.75 input) is still dramatically cheaper than Claude Sonnet 4.6 ($3.00 input). DeepSeek still undercuts everyone at the flagship tier on pure token price.

For budget use cases, GPT-4.1 nano ($0.10/M) and GPT-4o mini ($0.15/M) compete directly with Google's Gemini 3.1 Flash-Lite ($0.10/M).