GPT-4o mini Review: Specs, Pricing & Key Features

GPT-4o mini is the small, low-cost version of GPT-4o that OpenAI released on July 18, 2024. It replaced GPT-3.5 Turbo in ChatGPT, beat it on every major benchmark, and cost more than 60% less to run. For a year, it was the model behind countless chatbots, writing tools, and high-volume apps that needed good answers fast and cheaply.

This GPT-4o mini review covers what the model is, what its benchmarks showed, what it costs, how it compares with GPT-4o and the newer GPT-5 mini, and whether it still makes sense today. GPT-4o mini is available in Chat Smith on Android, iOS, and the web, so you can try it without an OpenAI account.

GPT-4o mini is a compact large language model from OpenAI's GPT-4o family. OpenAI built it for tasks where speed and cost matter more than maximum depth: chat replies, summaries, classification, short drafts, and apps that send many requests at once. Unlike later reasoning models, it answers directly without a separate thinking step.

It supports a 128,000-token context window and up to 16,000 output tokens per request, accepts text and images in the API, and has knowledge up to October 2023. Developers can also fine-tune it on their own data.

GPT-4o mini sat below the full model covered in our GPT-4o guide. In ChatGPT, it served free users and took over when people reached their GPT-4o limit, until OpenAI replaced it with the GPT-5 models in August 2025. Developers have continued to use it through the API.

Four strengths made GPT-4o mini the go-to small model of its time.

At launch, GPT-4o mini cost $0.15 per million input tokens and $0.60 per million output tokens, more than 60% cheaper than GPT-3.5 Turbo and a small fraction of GPT-4o's price. That made it practical to run AI on every message, search query, or support ticket, rather than saving it for special cases.

GPT-4o mini scored 82.0% on MMLU, a broad test of knowledge and reasoning, 87.0% on MGSM, a multilingual grade-school math test, and 87.2% on HumanEval for coding. Those results put it ahead of other small models at the time, such as Gemini Flash and Claude Haiku, and made it reliable for everyday math checks with tools like an AI math calculator.

GPT-4o mini can read images as well as text, scoring 59.4% on the MMMU multimodal benchmark. Its 128,000-token window lets it take in long documents or many messages of conversation history at once, which suits jobs like the ones an AI PDF summarizer handles.

GPT-4o mini was the first OpenAI model trained with its instruction hierarchy method, which helps it follow the developer's instructions over conflicting ones hidden in user messages or documents. That made it more resistant to jailbreaks and prompt injections, an important feature for public-facing chatbots.

The table compares GPT-4o mini with the full GPT-4o and with GPT-5 mini, the small model that replaced it. Scores are the ones OpenAI reported at each launch.

GPT-4o mini is still the cheapest of the three, but GPT-5 mini reasons far better on hard questions and images for a modest price increase. Our GPT-5 mini review covers its successor in detail.

In the OpenAI API, GPT-4o mini launched at $0.15 per million input tokens and $0.60 per million output tokens. Here is how access has changed since launch:

In Chat Smith, you can use GPT-4o mini without an OpenAI account. Free accounts include limited use, and Chat Smith Pro raises usage limits for $9.99 per month or $39.99 per year.

GPT-4o mini's knowledge stops in October 2023, so it will not know about recent events, products, or prices unless you give it that information. It also has no reasoning mode, which means it can stumble on multi-step math, logic, or planning that newer models handle easily.

Newer budget models have also overtaken it. GPT-5 mini reasons much better, and GPT-6 Luna now costs less per input token while offering a far larger context window, as our GPT-6 Luna review explains.

Finally, its benchmark scores date from 2024 and come from OpenAI's own testing. They show how it compared with small models of that era, not with today's options, so test it on your real tasks before relying on it.

GPT-4o mini is available in Chat Smith on Android, iOS, and the web. Pick it from the model list and start chatting, with no OpenAI account or ChatGPT subscription needed.

Use GPT-4o mini for quick replies, rewrites, and short summaries. When a question needs more careful thinking, switch to GPT-5 mini in the same chat, or try GPT-6 Luna, OpenAI's newest budget model.

You can also compare its answers with fast models from other labs, such as DeepSeek V4 Flash, and keep the one that holds up. For research-heavy questions, the built-in Deep Research feature runs advanced search and reasoning across sources.

GPT-4o mini made capable AI cheap enough to use everywhere: low prices, strong scores for its size, vision support, a long context window, and better protection against prompt injection. For simple, fast tasks, it still does the job well.

For anything that needs reasoning or up-to-date knowledge, newer models like GPT-5 mini and GPT-6 Luna are the better pick. You can try them side by side in Chat Smith, an AI chatbot that puts OpenAI's models next to the latest from Anthropic, Google, xAI, and DeepSeek.