OpenAI Models
GPT-5, GPT-4o, o3, and other OpenAI models
OpenAI creates some of the most popular AI models in the world. Their GPT series powers much of today's AI landscape. Here's everything you need to know about using OpenAI models in Billix.
Available Models
GPT-5
OpenAI's most advanced model.
| Attribute | Value |
|---|---|
| Best For | Complex reasoning, nuanced tasks |
| Speed | Medium |
| Cost | 20 credits |
| Context | 128K tokens |
When to use: Important tasks where quality matters most. Complex analysis, critical writing, sophisticated code.
GPT-4o
The best balance of speed and capability.
| Attribute | Value |
|---|---|
| Best For | General tasks, everyday use |
| Speed | Fast |
| Cost | 5 credits |
| Context | 128K tokens |
When to use: Your go-to model for most tasks. Writing, coding, questions, brainstorming.
GPT-4o Mini
Fast and affordable for simple tasks.
| Attribute | Value |
|---|---|
| Best For | Quick answers, simple tasks |
| Speed | Very Fast |
| Cost | 1 credit |
| Context | 128K tokens |
When to use: Simple questions, quick help, high-volume tasks where speed matters.
GPT-4.1
Optimized for coding and technical tasks.
| Attribute | Value |
|---|---|
| Best For | Code generation, debugging |
| Speed | Fast |
| Cost | 5 credits |
| Context | 128K tokens |
When to use: Writing code, debugging, code review, technical documentation.
o3
Advanced reasoning model that shows its thinking.
| Attribute | Value |
|---|---|
| Best For | Complex problem-solving |
| Speed | Slow |
| Cost | 20 credits |
| Context | 128K tokens |
When to use: Math problems, logical puzzles, tasks where you want to see step-by-step reasoning.
o4 Mini
Faster reasoning model.
| Attribute | Value |
|---|---|
| Best For | Reasoning with better speed |
| Speed | Medium |
| Cost | 5 credits |
| Context | 128K tokens |
When to use: When you need reasoning capabilities but don't want to wait for o3.
Choosing Between GPT Models
| Task | Best Model |
|---|---|
| Quick questions | GPT-4o Mini |
| General writing | GPT-4o |
| Creative content | GPT-5 |
| Coding | GPT-4.1 |
| Math/logic problems | o3 |
| Business documents | GPT-4o |
| Speed Need | Best Model |
|---|---|
| Instant | GPT-4o Mini |
| Fast | GPT-4o, GPT-4.1 |
| Medium | GPT-5, o4 Mini |
| Patient | o3 |
| Budget | Best Model |
|---|---|
| Tight (1 credit) | GPT-4o Mini |
| Standard (5 credits) | GPT-4o, GPT-4.1 |
| Premium (20 credits) | GPT-5, o3 |
Understanding Reasoning Models
What Are Reasoning Models?
Models like o3 and o4 Mini show their "thinking process" before giving you an answer. You'll see:
- Thinking - The model's internal reasoning
- Working through the problem - Step-by-step analysis
- Final answer - The conclusion
When to Use Reasoning Models
Good for:
- Math and logic problems
- Complex analysis
- Tasks where you need to verify the logic
- Learning how to approach problems
Not necessary for:
- Simple questions
- Creative writing
- Quick conversations
- Most everyday tasks
Image Generation with DALL-E
OpenAI's GPT Image 1 (DALL-E) can create images from text descriptions.
Select the Model
Choose "GPT Image 1" from the model selector.
Describe Your Image
Write a detailed description of what you want to create.
Generate
Send your message. The image will be generated and displayed.
Tips for better images:
- Be specific about style: "watercolor painting," "3D render," "photograph"
- Describe composition: "close-up," "wide angle," "bird's eye view"
- Include details: colors, lighting, mood, setting
Model Capabilities
What GPT Models Can Do
- Answer questions on any topic
- Write content (emails, essays, stories, code)
- Analyze and summarize documents
- Translate between languages
- Solve math and logic problems
- Generate and debug code
- Analyze images (GPT-4o, GPT-5)
- Create images (GPT Image 1)
What GPT Models Can't Do
- Access the internet in real-time (without search tools)
- Remember previous conversations (without Memory)
- Run code on your computer
- Access your files (unless uploaded)
- Make changes outside the conversation
Using Your Own API Key
If you have an OpenAI API key, you can use it directly:
Go to Settings
Open Settings → API Keys.
Add OpenAI Key
Paste your OpenAI API key.
Save
Your key is encrypted and stored securely.
With your own key:
- You're billed directly by OpenAI
- No Billix credit limits apply
- You get the same usage as OpenAI's API
Common Questions
Next Steps
- Explore Anthropic models (Claude)
- Learn about Google models (Gemini)
- Configure model settings
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