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Get started freeGPT-5.1 Codex vs Grok 3
Compare GPT-5.1 Codex and Grok 3. Build AI products powered by either model on Appaca.
Model Comparison
| Feature | GPT-5.1 Codex | Grok 3 |
|---|---|---|
| Provider | OpenAI | xAI |
| Model Type | text | text |
| Context Window | 400,000 tokens | 131,072 tokens |
| Input Cost | $1.25/ 1M tokens | $3.00/ 1M tokens |
| Output Cost | $10.00/ 1M tokens | $15.00/ 1M tokens |
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Build your first app freeStrengths & Best Use Cases
GPT-5.1 Codex
OpenAI1. Purpose-Built for Agentic Coding
- Designed specifically for environments where the model acts as an autonomous or semi-autonomous coding agent.
- Optimized for multi-step reasoning in code tasks such as planning, refactoring, debugging, file generation, and tool coordination.
2. Enhanced Coding Intelligence
- Extends GPT-5.1's advanced reasoning capabilities to handle complex software architecture decisions.
- Better accuracy in code generation across languages (JavaScript, Python, TypeScript, Go, Rust, etc.).
- Produces cleaner, more idiomatic code aligned with modern frameworks and best practices.
3. Superior Tool Use & Code Navigation
- Excels at reading, understanding, and transforming multi-file codebases.
- Works well with Codex workflows that simulate real developer tooling.
- Strong at following function signatures, constraints, and code patterns within an existing project.
4. Long-Range Context Awareness
- 400,000-token context window enables the model to ingest large repositories or multiple files simultaneously.
- Supports deep analysis of project structures, dependencies, and cross-file logic.
5. Multi-Modal Development Capabilities
- Accepts text + image input and output - suitable for tasks like:
- Reading UI mockups or screenshots to generate code
- Understanding architectural diagrams
- Reviewing images of whiteboard sessions
6. Agentic Workflow Optimization
- Built to manage longer chains of thought and execution typically required in:
- Automated code repair
- Project bootstrapping
- Linting and migration tasks
- Long-running coding agents using planning + execution loops
7. Continually Updated Model Snapshot
- Codex-specific version receives regular upgrades behind the scenes.
- Ensures the latest coding improvements without requiring developers to update model names.
8. Reliable Instruction Following
- Highly consistent in honoring explicit constraints:
- Code styles
- Folder structures
- API contracts
- Framework conventions
9. Broad API Support
- Works across Chat Completions, Responses API, Realtime, Assistants, and more.
- Ideal for apps that need live, reasoning-heavy coding agents or generative dev environments.
Grok 3
xAI1. Strong enterprise-grade reasoning
- Built for deep logical reasoning, structured decision-making, and multi-step analysis.
- Performs exceptionally in domains requiring precision: law, finance, healthcare, and STEM.
2. Excellent at data extraction and summarization
- Optimized for structured extraction from documents, PDFs, tables, and complex text.
- Ideal for enterprise workflows like reporting, compliance automation, or knowledge mining.
3. High-performance coding capabilities
- Excels at code generation, debugging, refactoring, and explaining code.
- Competitive with top-tier coding models for multi-file, long-context code reasoning.
4. Supports function calling and structured outputs
- Integrates cleanly with agent frameworks and external tools.
- Predictable, schema-aligned responses suitable for production systems.
5. Large 131K context window
- Handles long documents, transcripts, contracts, codebases, or multi-document tasks.
- Useful for ingesting highly technical materials in one pass.
6. Efficient cost structure with cached token pricing
- Cached inputs: only $0.75 / 1M tokens, enabling large-scale systems.
- Encourages reuse for powerful retrieval-augmented workflows.
7. Enterprise reliability and availability
- Supported across multiple regions (us-east-1, eu-west-1).
- Consistent rate limits: 600 requests/min.
- Suitable for production-grade apps with stability requirements.
8. Supports advanced search capabilities
- Optional Live Search add-on for real-time knowledge retrieval.
- Pricing: $25 per 1K sources.
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 Codex
textCommit Message Template
Write a structured commit message following conventional commits format.
Project Status Update
Write a concise status update for a project to share with stakeholders.
Sprint Retrospective Facilitation
Facilitate a productive sprint retrospective with structured prompts.
Best for Grok 3
textMaid of Honor Speech
Write a maid of honor speech that celebrates friendship, love, and the couple's journey. Heartfelt with just the right amount of fun.
Learning Goal Plan
Create a structured learning plan to acquire a new skill or knowledge area.
New Employee Onboarding Plan
Create a 30-60-90 day onboarding plan for a new hire.