1. Extremely low-cost text model

• One of the cheapest legacy models available.
• Suitable for very high-volume workloads with simple requirements.

2. Good for lightweight NLP tasks

• Classification, summarization, rewriting, paraphrasing, intent detection.
• Works for simple logic tasks and short reasoning sequences.

3. Works well for basic chatbots

• Optimized for Chat Completions API, originally powering early ChatGPT use cases.
• Good for rule-based or templated conversation flows.

4. Stable and predictable outputs

• Legacy behavior makes it suitable for systems built years ago that rely on its quirks.
• Good for backward compatibility or long-term enterprise pipelines.

5. Supports fine-tuning

• Useful for teams maintaining older fine-tuned GPT-3.5 models.
• Allows domain-specific compression of older datasets.

6. Limited capabilities compared to newer models

• No vision, no audio, no streaming, and no function calling.
• Much weaker reasoning and correctness vs GPT-4o mini or GPT-5.1.

7. Small context window (16K)

• Limited for multi-document tasks or long conversations.
• Best used for short, simple prompts or structured tasks.

8. Recommended migration path

• OpenAI explicitly recommends using GPT-4o mini instead.
• 4o mini is cheaper, smarter, faster, multimodal, and far more capable.

1. Flagship-level reasoning and math performance

• Designed for world-class reasoning depth, precision, and multi-step logical chains.
• Excels at STEM, mathematics, symbolic operations, proofs, and analytical workloads.

2. Powerful multimodal understanding

• Supports text, images, and other modalities.
• Handles cross-modal reasoning tasks requiring context synthesis.

3. Extreme capability across diverse tasks

• Positioned as a top-tier 'jack of all trades' model.
• Strong in natural language, coding, knowledge retrieval, and structured generation.

4. Large 256K context window

• Enables analysis of long documents, entire codebases, multi-document packs, and extensive agent sessions.
• Supports workloads that require persistent reasoning across large inputs.

5. Advanced developer tooling support

• Function calling for tool-augmented workflows.
• Structured outputs for predictable, schema-controlled generation.
• Integrates smoothly with agents and complex automation pipelines.

6. Efficient caching for cost reduction

• Cached input tokens discounted to $0.75 / 1M tokens.
• Encourages RAG, retrieval pipelines, and multi-step conversational workflows.

7. Production-ready performance

• Stable rate limits: 480 requests per minute.
• High token throughput: 2,000,000 tokens per minute.
• Available across multiple xAI regional clusters.

8. Optional Live Search augmentation

• Add-on: $25 per 1K sources.
• Enhances factual accuracy and real-time information retrieval.