Build AI products powered by GPT-5.1 or GPT-3.5 Turbo - no coding required
Start buildingGPT-5.1 vs GPT-3.5 Turbo
Compare GPT-5.1 and GPT-3.5 Turbo. Build AI products powered by either model on Appaca.
Get startedModel Comparison
| Feature | GPT-5.1 | GPT-3.5 Turbo |
|---|---|---|
| Provider | OpenAI | OpenAI |
| Model Type | text | text |
| Context Window | 400,000 tokens | 16,385 tokens |
| Input Cost | $1.25/ 1M tokens | $0.50/ 1M tokens |
| Output Cost | $10.00/ 1M tokens | $1.50/ 1M tokens |
Build with it | Build with GPT-5.1 | Build with GPT-3.5 Turbo |
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Power your AI product with GPT-5.1, GPT-3.5 Turbo, or any supported model. Switch anytime.
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Strengths & Best Use Cases
GPT-5.1
OpenAI1. Configurable Reasoning for Agentic Tasks
- Built to excel in autonomous or semi-autonomous coding workflows, with adjustable reasoning effort for planning, refactoring and debugging.
2. Fast Multi-Modal Input with Large Output
- Accepts both text and image inputs while producing text outputs.
- Offers up to 128 k output tokens, allowing long responses and code generation across multiple files.
3. Large Context & Knowledge Cut-Off
- 400 k token context window supports processing large codebases or documents.
- Knowledge cut-off of Sep 30 2024 ensures familiarity with recent tools and frameworks.
4. Reasoning Token Support
- Provides explicit support for reasoning tokens, enabling developers to fine-tune the balance between reasoning depth and speed.
GPT-3.5 Turbo
OpenAI1. 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.
Prompts to Get Started
Use these prompts to power AI products you build on Appaca. Each works great with the models above.
Best for GPT-5.1
textLead Nurturing Email Series (Education + Objections)
Create a lead nurturing email series that educates prospects, ties your USP to outcomes, and overcomes persona objections and challenges.
Instagram Caption Generator
Generate engaging Instagram captions that boost engagement and grow your following with scroll-stopping hooks and strategic hashtags.
Customer Onboarding Program (Activation + Value)
Create a customer onboarding program that reinforces your USP and sets your persona up for success overcoming their challenges.
Best for GPT-3.5 Turbo
textProfessional Email Rewriter
Rewrite your rough drafts into polished, professional emails suitable for any business context.
Craft Catchy Sales Emails
Write high-converting sales emails with strong hooks, clear value, and a single focused CTA-optimized for your audience and offer.
Email Subject Line Generator
Generate high-converting email subject lines that boost open rates using proven psychological triggers and A/B testing frameworks.
What AI product will you build?
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See how Appaca works
Turn your AI ideas into AI products with the right AI model
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Customer-facing Interface
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Multimodel LLMs
Create, manage, and deploy custom AI models for text, image, and audio - trained on your own knowledge base.
Agentic workflows and integrations
Create a workflow for your AI agents and tools to perform tasks and integrations with third-party services.
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“I've built with various AI tools and have found Appaca to be the most efficient and user-friendly solution.”
Cheyanne Carter
Founder & CEO, Edubuddy
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Build AI products powered by GPT-5.1 or GPT-3.5 Turbo
Create AI tools and agents on Appaca. Choose your model, build your product, launch to customers.