o3 vs GPT-3.5 Turbo
Compare pricing, context windows, and strengths for o3 by OpenAI and GPT-3.5 Turbo by OpenAI - and see how to put either to work in Appaca.
o3
A powerful reasoning model excelling at complex, multi-step tasks across math, science, coding, and visual reasoning; succeeded by GPT-5.
View o3GPT-3.5 Turbo
Legacy lightweight GPT model for cheap text generation and chat tasks; now replaced by faster, smarter, and cheaper 4o-mini models.
View GPT-3.5 Turboo3 vs GPT-3.5 Turbo at a glance
Specs and pricing side by side, from the Appaca AI models directory.
| Spec | o3 | GPT-3.5 Turbo |
|---|---|---|
| Provider | OpenAI | OpenAI |
| Model type | Text | Text |
| Context window | 200K tokens | 16.4K tokens |
| Input price | $2 / 1M tokens | $0.5 / 1M tokens |
| Output price | $8 / 1M tokens | $1.5 / 1M tokens |
| Status | Current | Current |
How o3 and GPT-3.5 Turbo differ
What the numbers mean in practice when choosing between o3 and GPT-3.5 Turbo.
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GPT-3.5 Turbo is 75% cheaper on input tokens ($0.5 vs $2 per million), which adds up quickly in document-heavy workloads.
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GPT-3.5 Turbo is 81% cheaper on output tokens ($1.5 vs $8 per million) - the bigger factor for tools that generate long documents.
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o3's 200K tokens context window is roughly 12.2x larger than GPT-3.5 Turbo's 16.4K tokens, so it can work across bigger codebases, contracts, or archives in one pass.
Strengths side by side
Where each model shines, according to benchmarks and provider positioning.
o3
1. Advanced reasoning capability
- Designed for multi-step thinking across text, code, and visual inputs.
- Excels at math, science, logic puzzles, and complex analytical workflows.
2. Strong performance across domains
- Highly capable in technical writing, data analysis, and structured problem-solving.
- Useful for research, engineering tasks, and intricate instruction-following.
3. Visual reasoning support
- Accepts image inputs, enabling tasks such as diagram analysis, chart interpretation, and visual logic assessments.
4. High output capacity
- Up to 100,000 output tokens, supporting long-form content, technical breakdowns, and multi-part solutions.
5. Excellent instruction following
- Produces detailed, step-by-step responses for tasks requiring precision and clarity.
- Ideal for educational explanations, system design reasoning, and code walkthroughs.
6. Large 200K context window
- Handles long documents, multi-file reasoning, or extended conversations with minimal loss of context.
7. Broad API support
- Works with Chat Completions, Responses, Realtime, Assistants, Batch, Embeddings, Image Generation, and more.
- Supports streaming and function calling for advanced workflows.
8. Positioned as a legacy reasoning model
- Remains extremely capable but formally succeeded by GPT-5, which offers stronger reasoning and performance.
GPT-3.5 Turbo
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.
Use o3 or GPT-3.5 Turbo - or both
Appaca is the AI workspace for operators. Build internal tools and AI co-workers powered by o3 or GPT-3.5 Turbo - connected to your real data and ready for your whole team. No code, no deployment.
Describe it, and it's built
Tell the Appaca agent the internal tool you need and it builds a working app powered by o3 or GPT-3.5 Turbo. No code, no API keys, no deployment.
Switch models without rebuilding
Start on o3, test the same tool on GPT-3.5 Turbo, and keep whichever performs better - the rest of your app stays exactly as it is.
Automated for the whole team
Schedule tools to run on autopilot - daily digests, weekly reports, real-time triggers - and share them with your whole team from one workspace.
Describe it, and it's built
Tell the Appaca agent what your team needs and it builds a working app powered by o3 or GPT-3.5 Turbo - connected to the tools you already use.
Related comparisons
See how o3 and GPT-3.5 Turbo stack up against other models in the directory.
FAQs
GPT-3.5 Turbo is generally cheaper: $0.5 input / $1.5 output per million tokens, versus $2 / $8 for o3. Actual cost depends on how many tokens your workload reads and writes.
o3 has the larger context window at 200K tokens, compared to 16.4K tokens for GPT-3.5 Turbo. A larger window means the model can consider more text at once - useful for long contracts, codebases, or months of records.
It depends on the job. Compare the pricing, context window, and strengths above against your workload - and remember the choice isn't permanent. In Appaca you can build a tool on o3, test the same tool on GPT-3.5 Turbo, and switch at any time without rebuilding anything.
Yes. Appaca is a no-code AI workspace: describe the internal tool your team needs and the Appaca agent builds it as a working app powered by o3, GPT-3.5 Turbo, or any other model in the directory - with a built-in database, team access, and integrations. No API keys to wire up and nothing to deploy.
Build AI tools with o3 or GPT-3.5 Turbo
Describe the tool your team needs and get a working app powered by the model you choose - with a built-in database, team access, and integrations. No code, no deployment.