How much does the GPT-5 nano API cost?

GPT-5 nano costs $0.05 per million input tokens and $0.4 per million output tokens, with cached input at $0.01 per million. A workload of 10M input and 1.5M output tokens per month costs about $1.10.

What is the context window of GPT-5 nano?

GPT-5 nano supports a context window of 400,000 tokens (400K), with up to 128K output tokens per response.

Is GPT-5 nano open source?

No — GPT-5 nano is a proprietary model available through OpenAI's API and partner platforms.

What are the best alternatives to GPT-5 nano?

The closest alternatives by overall capability are Qwen3-Max, Gemini 3 Pro, Gemini 2.5 Pro, DeepSeek V3.2. See the comparison pages for detailed head-to-head breakdowns.

GPT-5 nano

Name: GPT-5 nano
Price: 0.05 USD
Author: OpenAI

OpenAI·Aug 2025reasoningproprietary

GPT-5 nano is the smallest GPT-5 variant, priced for tasks where volume dwarfs difficulty: query routing, intent detection, moderation pre-filters and bulk metadata tagging. It keeps the 400K context window, which is unusual at this price point, making it handy for cheap first-pass scans over long documents before escalating to a bigger model.

Benchmark results

No verified benchmark results tracked yet for GPT-5 nano. This page is updated as official evaluations are published.

Where it shines

Lowest cost in the OpenAI lineup
Very low latency for real-time UX
400K context at commodity pricing

Alternatives to GPT-5 nano

Qwen3-Max

Alibaba's trillion-parameter API flagship — frontier-adjacent quality with strong agentic tool use at mid-tier prices.

Gemini 3 Pro

Google's November 2025 frontier breakout — 91.9% GPQA Diamond and 37.5% HLE made it the reasoning leader of its generation.

Gemini 2.5 Pro

Google's 2025 workhorse flagship — first mainstream thinking model with a 1M context, still widely deployed.

DeepSeek V3.2

The sparse-attention release that halved DeepSeek's already-lowest-in-class prices while keeping GPT-class quality.

Frequently asked questions

How much does the GPT-5 nano API cost?: GPT-5 nano costs $0.05 per million input tokens and $0.4 per million output tokens, with cached input at $0.01 per million. A workload of 10M input and 1.5M output tokens per month costs about $1.10.
What is the context window of GPT-5 nano?: GPT-5 nano supports a context window of 400,000 tokens (400K), with up to 128K output tokens per response.
Is GPT-5 nano open source?: No — GPT-5 nano is a proprietary model available through OpenAI's API and partner platforms.
What are the best alternatives to GPT-5 nano?: The closest alternatives by overall capability are Qwen3-Max, Gemini 3 Pro, Gemini 2.5 Pro, DeepSeek V3.2. See the comparison pages for detailed head-to-head breakdowns.