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Get started freeGPT-5 Codex vs Gemini 3 Pro
Compare GPT-5 Codex and Gemini 3 Pro. Build AI products powered by either model on Appaca.
Model Comparison
| Feature | GPT-5 Codex | Gemini 3 Pro |
|---|---|---|
| Provider | OpenAI | |
| Model Type | text | text |
| Context Window | 400,000 tokens | 1,000,000 tokens |
| Input Cost | $1.25/ 1M tokens | $4.00/ 1M tokens |
| Output Cost | $10.00/ 1M tokens | $18.00/ 1M tokens |
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Build your first app freeStrengths & Best Use Cases
GPT-5 Codex
OpenAI1. Purpose-Built for Agentic Coding
- Optimized specifically for scenarios where the model must act as an autonomous or semi-autonomous coding agent.
- Tailored for Codex workflows such as planning, editing, debugging, and multi-step tool-driven code tasks.
2. Advanced Coding Reasoning
- Extends GPT-5's higher reasoning mode to better handle complex software logic and multi-file dependencies.
- Produces more accurate, structured, and maintainable code across modern programming languages.
3. Strong Tool Use in Developer-Like Environments
- Designed for Codex's agent environment, enabling the model to:
- Read and modify files
- Follow function signatures and API contracts
- Navigate codebases with awareness of context and structure
4. Large Context Window for Full-Project Understanding
- 400,000-token context allows ingestion of:
- Entire repositories
- Multiple files at once
- Architectural descriptions
- Enables long-range reasoning across codebases rather than isolated snippets.
5. Multimodal Capability for Development Tasks
- Accepts text and image as input (great for screenshots of error logs, UI mocks, whiteboards).
- Outputs text only, focusing its output precision on code, reasoning, and documentation.
6. Continuous Snapshot Updates
- The underlying model version is regularly upgraded behind the scenes.
- Ensures developers always use the best coding-enhanced GPT-5 variant without changing model names.
7. Reliable Instruction Following
- Very strong adherence to constraints like:
- File/folder structure requirements
- Framework conventions
- Naming patterns
- Linting rules
- Makes it suitable for production coding agents.
8. Broad API Integration
- Available only in the Responses API, giving you:
- Streaming
- Structured outputs
- Function calling
- Allows creation of interactive coding tools and agent workflows with tight model control.
Gemini 3 Pro
Google1. State-of-the-art reasoning
- Top performance across academic reasoning, scientific knowledge, math, and complex problem-solving.
- Excels at long-horizon, multi-step workflows and deep logical interpretation.
2. World-leading multimodal capabilities
- Natively understands text, images, videos, audio, and code.
- Ranked highest on benchmarks like MMMU-Pro, Video-MMMU, ScreenSpot-Pro.
3. Exceptional coding + agentic workflows
- Strong in competitive coding and real-world agentic tasks (SWE-Bench Verified, Terminal-Bench, LiveCodeBench).
- Improved tool calling, planning, and execution for autonomous or semi-autonomous agents.
4. Powerful for long-context tasks
- Effective at 128K-1M context windows with high retrieval accuracy.
- Ideal for document-heavy workflows, research, analysis, multi-file coding, and multi-document reasoning.
5. Strong information synthesis and interpretation
- Outperforms peers in chart reasoning, OCR, structured extraction, and screen understanding.
- Excellent at combining multimodal inputs into coherent, concise answers.
6. High reliability for enterprise tasks
- Benchmarks show superior factuality, grounding, and parametric knowledge.
- Strong multilingual accuracy and global commonsense performance.
7. Optimized for production agents
- Designed for complex multi-step planning, simultaneous task execution, and improved consistency.
- Works across coding, research, creative workflows, UI generation, and data-heavy applications.
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 Codex
textIP Infringement Response Plan
Outline a response plan when receiving a notice of IP infringement.
New Employee Onboarding Plan
Create a 30-60-90 day onboarding plan for a new hire.
Structured Thinking Prompt
Use structured thinking prompts to work through a complex problem.
Best for Gemini 3 Pro
textCash Management Policy
Write a cash management policy for a small business or startup.
Financial Report Narrative
Write the management commentary narrative for a financial report.
Personal Budget Template
Create a personalised monthly budget framework based on income and spending.