What are AI Models?
AI models are the engine behind your AI Agent. They process input (like customer questions) and generate output (like answers). Each model has unique strengths in reasoning, speed, memory, and language capabilities. Understanding these differences helps you build a more effective AI Agent.How to choose the best model for your Agent?
1
Define your AI Agent’s primary function
Is it answering FAQs, guiding users through tasks, or automating actions?
2
Set your priorities
What is the most important thing the Agent should do?
- Speed: Do you want fast replies, or can the Agent take some more time?
- Length of answers: Does the Agent need to give long answers, or quick and short?
- Sources: How many sources does the Agent need for answering questions?
3
Pick the best model for your use case
Use the table below to find the best model for your situation:
| Use case | Examples | Recommended Models |
|---|---|---|
| Basic conversations (Customer service) | FAQ questions Delivery status checks Booking confirmations. | GPT-5-mini or GPT-4.1-mini: Both very fast models. GPT-5-mini is aware of date GPT-4.1-mini has a bigger context window |
| Longer/more complex customer journeys | Insurance claims Onboarding processes Resolving complex questions across multiple messages | GPT-4.1 or GPT-4.1-mini: Both have a large context memory GPT-4.1 is a bit smarter GPT-4.1-mini is faster. |
| Smart, complex conversations | Guiding customers through troubleshooting, legal compliance, or internal IT policies. | GPT-5 or o3. These models offer the highest reasoning. o3 has the highest reasoning of all, but takes a long time to generate answers. |
| Internal Support Agents (HR/IT/Finance related questions) | Handling leave requests Password resets Explaining payroll in natural language. | GPT-4.1-mini or GPT-5-mini for strong memory and high reasoning. GPT-4.1-mini has a bigger context window, GPT-5-mini is aware of date |
| Multilingual support | Support agents that switch smoothly between languages | GPT-5 or GPT-4.1 both have high reasoning and strong language capabilities. |
| Agent needs to know date and time | Responding to questions about reservations, new launches, pricing changes, or policy updates. | GPT-5.1, GPT-5, or GPT-5-mini. These Agents have awareness of date and time and also have the most recent knowledge cut off. |
| Agent needs to execute Actions | Agents that trigger workflows, create structured CRM entries, book meetings, or perform multistep automations. | Use GPT-5 or GPT-4.1 for their strong reasoning, structured outputs, and high capacity. GPT-5 will take longer to generate answers. |
Missing your use case in the above schedule?
Compare the different models below to find the best match. The questions below can help you.- Do you need fast responses? Go for a mini version of your preferred model
- Do you want the Agent to be able to handle a lot of information? Use a model with a high context window.
- Do you want the Agent to provide detailed answers? Go for a model with high output tokens.
- Do you want the Agent to think well, make connections, and solve complex tasks? Go for an Agent with high reasoning.
| Model | Reasoning | Speed | Input | Output | Context Window | Max Output Tokens | Knowledge Cutoff |
|---|---|---|---|---|---|---|---|
| GPT-5.1 | Highest | Medium | Text, Image | Text | 500,000 | 200,000 | Dec 01, 2024 |
| GPT-5 | Higher | Medium | Text, Image | Text | 400,000 | 128,000 | Oct 01, 2024 |
| GPT-5-mini | High | Fast | Text, Image | Text | 400,000 | 128,000 | May 31, 2024 |
| GPT-4.1 | Higher | Medium | Text, Image | Text | 1,047,576 | 128,000 | Jun 01, 2024 |
| GPT-4.1-mini | High | Fast | Text, Image | Text | 1,047,576 | 32,768 | Jun 01, 2024 |
| GPT-4o | High | Medium | Text, Image | Text | 128,000 | 16,384 | Oct 01, 2023 |
| o3 | Highest | Slowest | Text, Image | Text | 200,000 | 100,000 | Jun 01, 2024 |
| o3-mini | Higher | Medium | Text | Text | 200,000 | 100,000 | Oct 01, 2023 |