GPT-4.1 Nano: token counter & pricing

OpenAI · exact (uses official tokenizer) · pricing as of 2026-05-31.

Updated 2026-05-31 · By Clinton Patrick · Methodology

Provider: OpenAI
API model ID: gpt-4.1-nano
Context window: 1,000,000 tokens
Input price: $0.10 per 1M tokens
Output price: $0.40 per 1M tokens
Tokenizer accuracy: exact (uses official tokenizer)
Pricing as of: 2026-05-31

Open the counter to count tokens for GPT-4.1 Nano in real time.

What is GPT-4.1 Nano?

GPT-4.1 Nano is the cheapest tier of OpenAI's GPT-4.1 line, same 1M-token context window as full GPT-4.1, priced for high-volume workloads. $0.10 input / $0.40 output per 1M tokens.

It's the cheapest 1M-context exact-tokenizer model in OpenAI's catalog. Tied with Gemini 2.5 Flash-Lite on per-token rate ($0.10/$0.40) but with a different tokenizer and ecosystem.

How tokens are counted here

OpenAI's o200k_base tokenizer. Browser-side via js-tiktoken. Exact.

Pricing notes

$0.10 input / $0.40 output per 1M. Cached input $0.025/M.

Single-tier across the full 1M window, no surcharge above 128K. That's a real advantage for high-volume long-context workloads.

For 1,000 input + 200 output: $0.000180 per call, $180 per 1M calls.

When to use GPT-4.1 Nano

High-volume long-context classification or extraction, the cheapest exact-tokenizer 1M-context option.
OpenAI ecosystem fit, function calling, structured outputs, OpenAI's developer tooling.
Production-stable cheap tier, Nano is still on API after Feb 2026 ChatGPT retirement.

When not to use it:

Short-context only. GPT-5 Nano at $0.05 input is 50% cheaper and tied on output.
Multimodal workloads, Gemini 2.5 Flash-Lite handles image / video / audio at the same price tier.

Common questions

GPT-4.1 Nano vs GPT-5 Nano?

GPT-4.1 Nano: $0.10/$0.40, 1M context. GPT-5 Nano: $0.05/$0.40, 400K context. GPT-5 Nano is 50% cheaper on input and tied on output. Choose GPT-4.1 Nano only when you actually need the 1M context; otherwise GPT-5 Nano is the rational default.

GPT-4.1 Nano vs Gemini 2.5 Flash-Lite?

Tied on price ($0.10/$0.40). Flash-Lite has multimodal input (image / video / audio) and is positioned as the cheapest GA Gemini. GPT-4.1 Nano has OpenAI's more mature tool-use and function-calling. Pick by ecosystem.

Cached prompt savings?

Cached input at $0.025/M is 75% off standard. On agent loops with stable system prompts, this is the biggest cost lever, pays back almost immediately on any non-trivial volume.

Compare GPT-4.1 Nano to other models

GPT-5.5 (OpenAI, $5.00/$30.00)
GPT-5.5 Pro (OpenAI, $30.00/$180.00)
GPT-5.4 (OpenAI, $2.50/$15.00)
GPT-5.4 Mini (OpenAI, $0.75/$4.50)
GPT-5.4 Nano (OpenAI, $0.20/$1.25)
GPT-5.4 Pro (OpenAI, $30.00/$180.00)
GPT-5.3 (OpenAI, $1.75/$14.00)
GPT-5.2 (OpenAI, $1.75/$14.00)
GPT-5.2 Pro (OpenAI, $21.00/$168.00)
GPT-5.1 (OpenAI, $1.25/$10.00)
GPT-5 (OpenAI, $1.25/$10.00)
GPT-5 Mini (OpenAI, $0.25/$2.00)
GPT-5 Nano (OpenAI, $0.05/$0.40)
GPT-5 Pro (OpenAI, $15.00/$120.00)
GPT-4.1 (OpenAI, $2.00/$8.00)
GPT-4.1 Mini (OpenAI, $0.40/$1.60)
o3 (OpenAI, $2.00/$8.00)
o3-mini (OpenAI, $1.10/$4.40)
o3-pro (OpenAI, $20.00/$80.00)
o4-mini (OpenAI, $1.10/$4.40)
GPT-4o (OpenAI, $2.50/$10.00)
GPT-4o mini (OpenAI, $0.15/$0.60)
GPT-4 Turbo (OpenAI, $10.00/$30.00)
Gemini 2.5 Flash-Lite (Google, $0.10/$0.40)
Llama 3.1 8B (Meta, $0.18/$0.18)
Gemini 3.1 Flash-Lite (Google, $0.25/$1.50)