GPT-5.3 Codex vs Grok 4.20
GPT-5.3 Codex vs Grok 4.20: Grok 4.20 is cheaper for input-heavy usage ($1.25/M vs $1.75/M input tokens), while Grok 4.20 is better for long-context tasks (2,000,000 tokens).
Direct answer: choose Grok 4.20 for lower token spend and choose Grok 4.20 when your workload needs longer context.
Compare input and output token pricing, context windows, and monthly cost estimates on one page so you can pick the cheaper model fast.
Cost Comparison (1000 input + 500 output tokens, 100 requests/day)
GPT-5.3 Codex
Grok 4.20
Cost Differences
Grok 4.20 costs less than GPT-5.3 Codex
Quick Recommendation
Winner for direct API pricing: Grok 4.20. At the default workload, Grok 4.20 saves about $18.75/month ($228.125/year) versus GPT-5.3 Codex.
Feature Comparison
| Feature | GPT-5.3 Codex | Grok 4.20 |
|---|---|---|
| Provider | OpenAI | xAI |
| Input Price | $1.75/1M tokens | $1.25/1M tokens |
| Output Price | $14.00/1M tokens | $2.50/1M tokens |
| Context Window | 256,000 tokens | 2,000,000 tokens |
| Max Output | 32,768 tokens | 131,072 tokens |
| Category | coding | reasoning |
| Capabilities | textcode | textvisionreasoningcode |
| Release Date | 3/1/2026 | 2/17/2026 |
GPT-5.3 Codex vs Grok 4.20: Which Should You Choose?
Choosing between GPT-5.3 Codex and Grok 4.20 depends on your priorities: cost efficiency, context length, or raw capability. Grok 4.20 is the more affordable option at $1.25/1M input tokens — 29% cheaper than GPT-5.3 Codex. Meanwhile, Grok 4.20 offers a significantly larger context window at 2,000,000 tokens vs 256,000 for GPT-5.3 Codex.
These models come from different providers — OpenAI and xAI — which means different API ecosystems, SDKs, rate limits, and terms of service. If you're already integrated with OpenAI, switching to xAIinvolves migration effort beyond just pricing. Factor in your existing infrastructure when deciding.
These models target different tiers: GPT-5.3 Codex is a coding model while Grok 4.20 is reasoning. This means they're optimized for different workloads. Grok 4.20 targets more demanding workloads, while GPT-5.3 Codex provides a cost-effective option for everyday tasks.
Output costs matter too. GPT-5.3 Codex charges $14.00/1M output tokens vs $2.50 for Grok 4.20. For generation-heavy workloads (content creation, code generation, summarization), output pricing often dominates your bill. Grok 4.20 has the edge here at $2.50/1M output tokens.
Multimodal capabilities: Grok 4.20 supports vision (image inputs) while GPT-5.3 Codex is text-only. If your application needs image understanding, this narrows your choice.
Best Use Cases
Choose GPT-5.3 Codex when:
- • You're already using OpenAI's API ecosystem
Choose Grok 4.20 when:
- • Budget is a primary concern
- • You need a larger context window (2,000,000 tokens)
- • You need more capabilities (vision, reasoning)
- • You need longer outputs (up to 131,072 tokens)
- • You're already using xAI's API ecosystem
Pros and Caveats at a Glance
GPT-5.3 Codex
- • Input pricing: $1.75/M tokens
- • Output pricing: $14.00/M tokens
- • Context window: 256,000 tokens
- • Max output: 32,768 tokens
Watch out for
- • Higher input cost than Grok 4.20
- • Higher output cost than Grok 4.20
- • Smaller context window than Grok 4.20
Grok 4.20
- • Input pricing: $1.25/M tokens
- • Output pricing: $2.50/M tokens
- • Context window: 2,000,000 tokens
- • Max output: 131,072 tokens
Watch out for
- • Trade-offs are minor in this matchup.
Try Different Scenarios
Use the calculator below to see how costs change with different usage patterns
GPT-5.3 Codex (OpenAI)
Grok 4.20 (xAI)
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Which is cheaper, GPT-5.3 Codex or Grok 4.20?▼
What is the context window difference between GPT-5.3 Codex and Grok 4.20?▼
Which model is better for AI Chatbot?▼
Which model has better overall pricing for heavy usage?▼
Where can I compare OpenAI and xAI API pricing beyond this model matchup?▼
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