GPT-5.4 Mini & Nano Launch: Lightweight, Cost-Effective Models Built for Scale

OpenAI released GPT-5.4 Mini and Nano on March 17, 2026. Mini runs 2x faster than GPT-5 Mini, Nano costs just $0.20/M input tokens. Now available on APIYI at official pricing with ~10% deposit bonus.

Key Highlights

• Most Capable Small Models: GPT-5.4 Mini significantly improves over GPT-5 Mini across coding, reasoning, multimodal understanding, and tool use — over 2x faster
• Ultra Cost-Effective: GPT-5.4 Nano at just $0.20/M input tokens and $1.25/M output tokens, the cheapest GPT-5.4 family model
• Near-Flagship Performance: Mini scores 54.4% on SWE-Bench Pro and 72.1% on OSWorld-Verified, approaching full GPT-5.4
• 400K Context Window: Consistent with the GPT-5 family
• Full Capabilities: Text & image input, tool calling, web search, computer use — all supported

Background

On March 17, 2026, OpenAI officially released GPT-5.4 Mini and GPT-5.4 Nano, calling them “the most capable small models yet.” Following the GPT-5.4 flagship launch in early March, this release brings 5.4-level capabilities to lightweight, cost-efficient models.

GPT-5.4 Mini targets developers who need high performance on a budget, delivering near-flagship quality at a fraction of the cost. GPT-5.4 Nano is purpose-built for high-throughput, low-cost workloads like classification, data extraction, ranking, and coding subagents.

APIYI has immediately launched both models at pricing identical to OpenAI’s official rates, with official API proxy and ~10% deposit bonus.

Detailed Analysis

Core Features

2x Faster

GPT-5.4 Mini runs more than 2x faster than GPT-5 Mini with significantly lower latency

Ultra-Low Pricing

Nano can describe 76,000 photos for approximately $52

Near-Flagship

Mini scores 54.4% on SWE-Bench Pro (vs GPT-5.4’s 57.7%)

Full Capabilities

Image understanding, tool calling, web search, computer use — all included

GPT-5.4 Mini Benchmarks

GPT-5.4 Mini dominates across evaluations compared to GPT-5 Mini:

Benchmark	GPT-5.4 Mini	GPT-5.4 (Full)	GPT-5 Mini	Description
SWE-Bench Pro	54.4%	57.7%	45.7%	Real-world software engineering
OSWorld-Verified	72.1%	75.0%	42.0%	Computer use benchmark
Toolathlon	42.9%	—	26.9%	Tool calling evaluation
GPQA Diamond	88.0%	—	81.6%	Research-level science reasoning
Tau2-Bench	93.4%	—	74.1%	Tool calling benchmark
MCP Atlas	57.7%	—	47.6%	MCP protocol evaluation
Terminal-Bench 2.0	60.0%	—	—	Terminal operation evaluation

GPT-5.4 Mini scores 72.1% on OSWorld-Verified, a 71.7% improvement over GPT-5 Mini’s 42.0%, approaching the flagship GPT-5.4’s 75.0%.

GPT-5.4 Nano Performance

Nano is the smallest, cheapest GPT-5.4 variant, designed for speed and cost-first scenarios:

Benchmark	GPT-5.4 Nano	GPT-5.4 Mini
Terminal-Bench 2.0	46.3%	60.0%
OSWorld-Verified	39.0%	72.1%

OpenAI recommends Nano for classification, data extraction, ranking, and coding subagents handling simpler supporting tasks.

Adjustable Reasoning Effort

Both models support variable reasoning effort levels for flexible cost-performance tradeoffs:

• none: No reasoning, fastest response
• low / medium / high: Increasing reasoning depth
• xhigh: Maximum reasoning effort

Notably, GPT-5.4 Nano at maximum reasoning effort outperforms the previous GPT-5 Mini, achieving last-generation mid-tier capabilities at a fraction of the cost.

Practical Applications

Recommended Use Cases

GPT-5.4 Mini:

1. Coding Assistant: 54.4% SWE-Bench Pro, ideal for code generation, review, and debugging
2. Autonomous Agents: 72.1% OSWorld, supports computer use and multi-step workflows
3. Daily Chat: Default thinking model for ChatGPT Free and Go users
4. OpenClaw & Similar: High performance at low cost, perfect for batch intelligent tasks

GPT-5.4 Nano:

1. Data Pipelines: Classification, extraction, ranking at high throughput
2. Coding Subagents: Handle simpler supporting tasks in agent architectures
3. Batch Image Understanding: ~$52 for 76,000 photo descriptions
4. Real-time Classification: Ultra-low latency, ultra-low cost

Code Examples

Using GPT-5.4 Mini

from openai import OpenAI

client = OpenAI(
    api_key="your-apiyi-key",
    base_url="https://api.apiyi.com/v1"
)

# GPT-5.4 Mini - Cost-effective coding assistant
response = client.chat.completions.create(
    model="gpt-5.4-mini",
    messages=[
        {
            "role": "user",
            "content": "Refactor this code to extract common logic and add error handling..."
        }
    ],
    max_tokens=4096
)

print(response.choices[0].message.content)

Using GPT-5.4 Nano for Batch Processing

# GPT-5.4 Nano - Ultra cost-effective batch tasks
response = client.chat.completions.create(
    model="gpt-5.4-nano",
    messages=[
        {
            "role": "system",
            "content": "You are a text classifier. Classify user input as: positive, negative, or neutral. Output only the classification."
        },
        {
            "role": "user",
            "content": "This product is excellent quality, will definitely buy again!"
        }
    ],
    max_tokens=10
)

print(response.choices[0].message.content)

Pricing & Availability

Pricing

Tier	GPT-5.4 Nano	GPT-5.4 Mini	GPT-5.4 (Full)
Input	$0.20 / M tokens	$0.75 / M tokens	$2.50 / M tokens
Cached Input	$0.02 / M tokens	$0.075 / M tokens	—
Output	$1.25 / M tokens	$4.50 / M tokens	$15.00 / M tokens

GPT-5.4 Mini costs just 30% of the flagship GPT-5.4 with near-flagship performance. Nano is only 8% of flagship cost — ultimate value.

Competitive Comparison:

Model	Input Price	Output Price	Positioning
GPT-5.4 Nano	$0.20	$1.25	Ultra-lightweight
GPT-5.4 Mini	$0.75	$4.50	Cost-effective
Gemini 3.1 Flash Lite	$0.25	$0.50	Lightweight fast
Claude Haiku 4.5	$0.80	$4.00	Fast response
GPT-5.2 mini	$0.30	$1.80	Previous-gen small model

Promotions

View Latest Deposit Bonus Offers

APIYI offers deposit bonuses — official API proxy with ~10% bonus on deposits. Pricing matches official rates, with effective discounts through deposit bonuses.

Available Models

Model Name	Variant	Context	Description
gpt-5.4-mini	Mini	400K	Cost-effective, near-flagship performance
gpt-5.4-nano	Nano	400K	Ultra-low cost, high-throughput scenarios

How to Access

APIYI Platform:

• Website: apiyi.com
• API Endpoint: https://api.apiyi.com/v1
• OpenAI-compatible format, works with all OpenAI SDKs
• Official API proxy, stable and reliable

Summary & Recommendations

GPT-5.4 Mini and Nano bring flagship-level capabilities to developers and applications at dramatically lower costs.

Key Advantages:

• Mini: Flagship-tier capability at 30% cost, 2x speed
• Nano: Ultra-low pricing at 8% of flagship cost, built for scale

Selection Guide:

1. Near-flagship performance needed: Choose GPT-5.4 Mini (SWE-Bench Pro 54.4%, OSWorld 72.1%)
2. High-throughput batch processing: Choose GPT-5.4 Nano ($0.20/M input tokens)
3. Agent architecture subtasks: Nano as execution layer, Mini as decision layer
4. OpenClaw & similar: Both Mini and Nano work well — choose based on cost-performance needs
5. Cost-insensitive professional tasks: Still recommend GPT-5.4 flagship or Pro

APIYI has launched both GPT-5.4 Mini and Nano at official pricing with ~10% deposit bonus. Experience OpenAI’s most capable lightweight models today!

Sources: OpenAI official blog (March 17, 2026), 9to5Mac, The New Stack, Simon Willison’s Weblog, and other authoritative sources. Data retrieved: March 18, 2026.