How to Use O1-preview and O1-mini Free

Getting Started with OpenAI o1-preview and o1-mini

OpenAI recently shifted how their AI models process information. Most users are accustomed to the instant responses of GPT-4o, but the new o1 series operates differently. These models, specifically o1-preview and o1-mini, use a process called reinforcement learning to "think" before they speak. They spend time walking through a private chain of thought to solve complex problems in math, science, and coding. If you have tried to get ChatGPT to solve a difficult logic puzzle in the past, you might have noticed it sometimes hallucinates or skips steps. The o1 models aim to fix that by double-checking their work before the text ever appears on your screen.

Many users are looking for ways to access these tools without paying the full price of a monthly subscription. Here's the thing: OpenAI currently restricts these reasoning models to paid tiers. You cannot find them on the standard free version of ChatGPT right now. However, if you have a Plus subscription, you get access to both models within certain usage limits. This allows you to test the most advanced reasoning capabilities available in the consumer market today.

What the o1 Series Actually Does

The o1-preview and o1-mini models are not just incremental updates to GPT-4. They represent a new class of "reasoning" models. When you send a prompt, you will see a status indicator that says "Thinking." During this time, the model is breaking your request into smaller logical steps. It tries different approaches and corrects its own mistakes internally. This results in much higher accuracy for tasks that require multi-step planning.

The o1-preview Model

This is the larger, more capable version of the two. It is built for broad reasoning across many different domains. It features a 128K token context window, which means it can process a massive amount of text in a single conversation. It can generate up to 32K tokens in a single response. In technical benchmarks, it performs significantly better than GPT-4o in PhD-level science questions and complex coding challenges. It is the model you choose when the problem is deeply nuanced or requires a broad understanding of multiple subjects. Processing is slower here, averaging about 23 tokens per second.

The o1-mini Model

OpenAI designed o1-mini to be a faster and more efficient alternative. It is particularly optimized for STEM tasks like math and coding. Despite being smaller, it holds its own against o1-preview in coding benchmarks, scoring 48.9% on the SWE-bench. It also uses a 128K context window but offers a larger output capacity of up to 65.5K tokens. The speed is a major selling point. It processes at roughly 73.9 tokens per second, making it feel much more responsive than its larger sibling. If you are debugging code or solving calculus problems, this is usually the better tool to use.

Current Limitations

These models are currently in a beta phase, which means they lack several features found in GPT-4o. They are text-only. You cannot upload images for them to analyze, and they cannot generate images using DALL-E. They do not have access to the internet for web browsing. You cannot upload files for them to read. They do not support "system messages," which are the custom instructions power users often use to set a specific tone or persona for the AI. These models are purely for logic and text-based problem solving.

Access Requirements and Plans

To use o1-preview and o1-mini, you must have a specific type of account. Free users are currently excluded from the beta. OpenAI has stated they plan to bring o1-mini access to free users eventually, but they have not provided a specific date for that rollout.

Currently, the following groups have access:

• ChatGPT Plus subscribers ($20 per month).
• ChatGPT Team and Enterprise users.
• ChatGPT Edu users.
• API developers in Tier 5 (those who have spent $1,000 or more on the platform).

If you are a casual user, the Plus subscription is the standard entry point. This gives you a specific number of messages you can send to these models each week or day. These quotas are subject to change as OpenAI manages server load during the beta period.

Practical Ways to Get Access for Less

The standard $20 monthly fee for ChatGPT Plus is the most direct way to get these models. It includes GPT-4o, Advanced Voice Mode, and DALL-E. For many people, that price is a bit steep for a single tool. There are a few ways to manage the cost or find alternatives.

One option is to use the OpenAI API. This is a pay-as-you-go system. You don't pay a monthly fee, but you pay for every word the AI reads and writes. O1-preview is expensive via API, costing $15 per million input tokens and $60 per million output tokens. O1-mini is significantly cheaper at $3 per million input and $15 per million output. This is only practical if you know how to use API tools or third-party interfaces.

Another option is AccsUpgrade. This service provides access to ChatGPT Plus features at a lower price point. Instead of the $20 retail price, they offer access for about 7.5. This can be a useful choice if you want to test the o1 models without committing to the full retail subscription. The tradeoff is that you are using a managed account service rather than a direct personal subscription from OpenAI. It is a budget-friendly way to get the same reasoning capabilities for less than half the price.

How to Use o1-preview and o1-mini Step-by-Step

Once you have a Plus account or access through a service like AccsUpgrade, using the models is straightforward. They are integrated directly into the ChatGPT interface.

1. Log in to your ChatGPT account on a web browser or the mobile app.
2. Look for the model selector at the top of the chat window. It usually defaults to GPT-4o.
3. Click or tap the dropdown menu to see the list of available models.
4. Select "o1-preview" for deep logic or "o1-mini" for faster coding and math tasks.
5. Type your prompt into the chat box. Try to be as descriptive as possible.
6. Press enter and wait. You will see a "Thinking" dropdown. You can click this to see which step of the reasoning process the AI is currently on.
7. Review the final response. Since the model has already "checked" its logic, the answer is typically more structured and accurate than standard models.

Remember that your message count is limited. If you select o1-preview, try to save it for your most difficult questions. If you are just chatting or asking for a summary of a simple email, GPT-4o is better because it doesn't count against your o1 quota.

Common Access Blockers and Fixes

You might run into issues even if you have a paid account. The most common problem is hitting the message limit. As of the current beta, o1-preview is limited to 50 messages per week. O1-mini allows for 50 messages per day. If you hit these limits, the model will be greyed out in the menu, and you will have to wait for the timer to reset. There is no way to "buy" more messages within the Plus plan once you hit the cap.

Another issue is the lack of multimodal support. If you try to upload an image or a PDF while o1-preview is selected, the interface will often tell you that the feature is not supported. You must switch back to GPT-4o to use those tools. Look at the icons in the text box. If the paperclip or camera icon is missing or disabled, it is because you are using a reasoning model that only accepts text.

Sometimes the model selector doesn't appear at all. This usually happens if your subscription has lapsed or if OpenAI is experiencing a regional outage. Refreshing the page or logging out and back in usually fixes minor interface glitches. If you are using a third-party service, ensure your account status is active on their dashboard.

Frequently Asked Questions

Can I use o1-preview for free?

No. Currently, there is no official free tier for the o1 models. You must have a ChatGPT Plus, Team, Enterprise, or Edu subscription. OpenAI has mentioned a plan to bring o1-mini to free users in the future, but that has not happened yet. Some third-party platforms might offer limited trials, but these are not official OpenAI offerings.

Why is o1-preview so slow compared to GPT-4o?

The speed difference is intentional. Standard models predict the next word in a sequence very quickly. Reasoning models are designed to stop and think. They generate an internal chain of thought that can be thousands of words long before they show you a single word of the final answer. This extra processing time is what allows them to solve complex problems more accurately.

Is o1-mini better than o1-preview for coding?

In many cases, yes. While o1-preview is smarter across a wider range of general topics, o1-mini is specifically tuned for STEM. It is much faster and often provides code that is just as accurate as the larger model. It also has a higher output token limit, which is helpful when the AI needs to write long scripts or multiple files at once.

Does using these models count against my GPT-4o limits?

No. The o1 models have their own separate quotas. Using your 50 weekly messages for o1-preview will not affect your ability to use GPT-4o. This allows you to use the reasoning models for hard tasks and the standard models for everything else throughout the day.

Final Thoughts

The o1 series represents a significant shift in how we interact with AI. It moves away from instant, sometimes shallow responses toward a more deliberate and logical approach. While the cost of entry is currently tied to a $20 monthly subscription, options like AccsUpgrade provide a way to access these tools for a lower price. If you find yourself frustrated by AI making simple logic errors or failing at complex code, these reasoning models are the correct tool for the job. Start with o1-mini for your technical tasks to see the speed benefits, and save o1-preview for the truly difficult logic puzzles that other models can't solve.