How to Use GPT-4.1 API Free, Unlimited with Windsurf (For Now)

In the rapidly evolving world of artificial intelligence, OpenAI's latest model family, GPT-4.1, represents a significant leap forward in capabilities. This cutting-edge technology is now accessible for free through Windsurf, providing developers with an unprecedented opportunity. This article explores GPT-4.1's capabilities, its pricing structure, and provides detailed guidance on how to utilize this powerful AI model for free with the Windsurf platform.

GPT-4.1: Benchmarks and API Pricing

OpenAI recently unveiled GPT-4.1, a new series of models specifically designed to excel at coding tasks, instruction following, and handling extremely long contexts. This release marks a significant advancement in AI capabilities, particularly for developers and technical professionals.

GPT 4.1 Performance Benchmarks

According to OpenAI's official benchmarks, GPT-4.1 demonstrates remarkable improvements over its predecessors:

• Coding Performance: GPT-4.1 scores an impressive 54.6% on SWE-bench Verified, representing a substantial improvement of 21.4% absolute points over GPT-4o and 26.6% absolute points over GPT-4.5. This positions GPT-4.1 as a leading model for software engineering tasks.
• Instruction Following: The model shows enhanced abilities to understand and execute complex multi-step instructions, making it more reliable for advanced development workflows.
• Long Context Handling: GPT-4.1 can process up to 1 million tokens, enabling developers to work with entire codebases and extensive documentation simultaneously.

GPT 4.1 API Pricing Structure

OpenAI has implemented a competitive pricing structure for the GPT-4.1 family, which includes three variants with different performance-cost tradeoffs:

1. GPT-4.1: The flagship model, offering the highest performance for complex coding and reasoning tasks.
2. GPT-4.1-mini: A balanced option designed to provide strong performance while optimizing for speed and cost.
3. GPT-4.1-nano: The most affordable option, suitable for simpler tasks while still delivering reliable results.

In a notable move to increase accessibility, OpenAI has reduced GPT-4.1 API prices by up to 75% compared to previous models, initiating what some industry observers call an "AI price war" among major technology providers. This pricing strategy reflects OpenAI's commitment to making advanced AI technologies more accessible to developers and businesses of all sizes.

Free Access to GPT-4.1 Through Windsurf

While GPT-4.1 represents a significant advancement in AI technology, accessing it through OpenAI's API typically requires payment. However, Windsurf, an AI-enhanced coding platform developed by Codeium, is currently offering a remarkable opportunity for developers.

For the next seven days, get free unlimited GPT-4.1 on Windsurf, on us.

That’s right, free.

We are very excited about GPT-4.1 given our internal evals. We have rate limits to prevent abuse, so go build without worrying about credits. pic.twitter.com/xBZS9UmUVb

— Windsurf (@windsurf_ai) April 14, 2025

The Windsurf Free Access Promotion

Windsurf has announced an exciting promotion: "For the next seven days, get free unlimited GPT-4.1 on Windsurf, on us. That's right, free."

This limited-time offer allows developers to experience the full capabilities of GPT-4.1 without worrying about API costs or usage limitations. According to Windsurf's announcement, their internal evaluations of GPT-4.1 were so impressive that they decided to provide this opportunity to their user community.

While the offer includes "unlimited" access to GPT-4.1, Windsurf has implemented reasonable rate limits to prevent system abuse. These limits are designed to be generous enough for genuine development work, allowing users to focus on building projects rather than monitoring credit usage.

Why Windsurf?

Windsurf has quickly gained recognition as a powerful AI-enhanced code editor where "the work of developers and AI truly flow together." The platform is designed specifically for developers working with large codebases, providing context-aware AI assistance that understands your entire project structure.

By combining Windsurf's code-centric features with GPT-4.1's enhanced capabilities, developers gain access to:

• Advanced code generation and completion
• Sophisticated debugging assistance
• Intelligent code refactoring suggestions
• Comprehensive documentation generation
• Context-aware answers to complex programming questions

How to Enable OpenAI's Key Within Windsurf: Step-by-Step Guide

To take advantage of Windsurf's free GPT-4.1 promotion, you'll need to set up the platform correctly. Follow these detailed steps to get started:

Step 1: Create Your Accounts

Sign up for Windsurf:

• Visit the Windsurf website at codeium.com/windsurf
• Complete the registration process by providing your email address and creating a password
• Verify your email address through the confirmation link sent to your inbox

Create an OpenAI Account (if you don't already have one):

• Go to openai.com and sign up for a new account
• Complete the verification process
• Note that while you need an OpenAI account, you won't need to pay for API usage during Windsurf's free promotion period

Step 2: Download and Install Windsurf

1. Navigate to the Windsurf download page from your account dashboard
2. Select the appropriate version for your operating system (Windows, macOS, or Linux)
3. Download the installer and run it on your system
4. Follow the on-screen instructions to complete the installation process

Step 3: Set Up Your OpenAI API Key

Although Windsurf is offering free access to GPT-4.1, you'll still need to configure your OpenAI API key within the platform:

Generate an API Key from OpenAI:

• Log in to your OpenAI account at platform.openai.com
• Navigate to the "API Keys" section
• Click "Create new secret key" and provide a name for your key (e.g., "Windsurf Integration")
• Copy the generated API key immediately, as OpenAI will not show it again

Add Your API Key to Windsurf:

• Launch the Windsurf application on your computer
• Click on your profile icon in the top-right corner
• Select "Settings" from the dropdown menu
• Navigate to the "Integrations" or "API Keys" section
• Paste your OpenAI API key in the designated field
• Click "Save" or "Connect" to establish the integration

Step 4: Verify and Configure GPT-4.1 Access

1. In Windsurf's settings, look for the "AI Models" or "Language Models" section
2. Ensure that GPT-4.1 is selected as your preferred model
3. Confirm that the "Free Access Promotion" indicator is active
4. Optionally, adjust any model-specific settings according to your preferences

Step 5: Start Using GPT-4.1 in Your Projects

1. Open or create a project within Windsurf
2. Access GPT-4.1 capabilities through:

• The command palette (typically accessible via Ctrl+Shift+P or Cmd+Shift+P)
• Context menu options when right-clicking on code
• AI-assisted code completion as you type
• The chat interface for direct queries

Testing GPT 4.1 API Requests with Apidog

When working with the GPT 4.1 API, testing and debugging your requests is crucial to ensure they work as expected. This is where Apidog comes in. Apidog is a powerful API management tool that simplifies the process of sending, testing, and analyzing API requests.

Step 1: Set Up Apidog

After downloading and installing Apidog, create a new project. Add a new API request by selecting the HTTP method POST and entering the GPT 4.1 API endpoint URL (you can find this in the Google AI Studio documentation).

Step 2: Configure the Request

In Apidog, set the following:

• Headers: Add Authorization: Bearer YOUR_API_KEY.
• Body: Use a JSON structure to define your request.

Step 3: Send and Analyze the Request

Click the “Send” button in Apidog to execute the request. Apidog will display the response, including the status code, response time, and the actual response body. This allows you to quickly identify any issues, such as authentication errors or incorrect payloads.

Step 4: Optimize Your Requests

Apidog also provides tools to save and reuse requests, set up automated tests, and monitor API performance. For example, you can create a test case to verify that the API returns a valid response for different prompts, ensuring your integration is robust.

By using Apidog, you can streamline your development workflow and ensure your GPT 4.1 API integration is efficient and error-free. Let’s move on to advanced use cases.

Conclusion

The combination of GPT-4.1's advanced capabilities and Windsurf's free access promotion represents an extraordinary opportunity for developers looking to enhance their productivity and explore cutting-edge AI assistance. By following the steps outlined in this article, you can quickly set up and begin leveraging GPT-4.1's powerful features at no cost.

Remember that while the free promotion is time-limited, the experience and insights gained from working with such advanced AI technology will continue to benefit your development process long after the promotion ends. Whether you're a professional developer, a student, or an AI enthusiast, this is an ideal time to experience firsthand how the latest advancements in large language models can transform the coding experience.

Don't miss this limited window to experience the future of AI-assisted development with GPT-4.1 on Windsurf—completely free.