OpenAI API API pricing: plans, free tier and what to watch for

OpenAI API API pricing at a glance: GPT-5.5 (flagship) $5.00 / $30.00 per 1M tokens, GPT-5.4 $2.50 / $15.00 per 1M tokens, GPT-5.4-mini $0.75 / $4.50 per 1M tokens, GPT-5.4-nano $0.20 / $1.25 per 1M tokens

The short answer

OpenAI API is billed per token. It has no free tier ($5 trial credit (after ID verification); opt-in data-sharing free tokens). The paid plans we list start at $5.00 / $30.00 per 1M tokens (GPT-5.5 (flagship)).

Plans and prices

Plan	Price	What it covers
GPT-5.5 (flagship)	$5.00 / $30.00 per 1M tokens	Input / output; cached input $0.50/1M. Highest-intelligence model (AA Index 55).
GPT-5.4	$2.50 / $15.00 per 1M tokens	Input / output; cached input $0.25/1M. Mid-tier flagship.
GPT-5.4-mini	$0.75 / $4.50 per 1M tokens	Input / output; cached input $0.075/1M. Cost-efficient general model.
GPT-5.4-nano	$0.20 / $1.25 per 1M tokens	Input / output; cached input $0.02/1M. Cheapest, lowest-latency tier (~0.56s TTFT).
Batch / Flex processing	Up to ~50% off standard	Asynchronous Batch API and Flex tier trade latency for substantially lower per-token cost.
Scale Tier	Custom / committed throughput	Prioritized compute with a contractual 99.9% uptime SLA for production traffic.

How OpenAI API bills you

The pricing model is per token. The default LLM API most teams reach for first, with the deepest docs, tooling, and third-party ecosystem. Best suited to: frontier general-purpose llm platform.

What to watch for on the bill

Expensive output tokens on flagship models ($30/1M on GPT-5.5) make high-volume generation costly
Standard pay-as-you-go tier has no uptime SLA; guarantees require Scale Tier or Azure
Recurring billing-transparency and credit-reconciliation complaints from users
New/low-tier accounts hit restrictive rate limits and quota-ramp friction

The pricing page we read

OpenAI API pricing page, captured for reference — Capture of developers.openai.com. Captured from Germany, so some vendors show local prices or currency. Listed prices are verified Jun 27, 2026. The live page may differ.

Source: https://developers.openai.com/api/docs/pricing. Prices change, so confirm there before you commit.

Compare OpenAI API with alternatives

Other llm apis: Anthropic Claude API, Google Gemini API, Mistral La Plateforme, xAI Grok API, Groq.

Looking at quality rather than price? See the OpenAI API score on APIbenchmarks. Full entry: OpenAI API pricing.