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Get started freeGPT-5.1 Codex vs Grok 4
Compare GPT-5.1 Codex and Grok 4. Build AI products powered by either model on Appaca.
Model Comparison
| Feature | GPT-5.1 Codex | Grok 4 |
|---|---|---|
| Provider | OpenAI | xAI |
| Model Type | text | text |
| Context Window | 400,000 tokens | 256,000 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 4
xAI1. 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.
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
textTechnical Interview Questions
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Security Threat Model
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Best for Grok 4
textPeer Assessment Guide
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