Model comparison

GPT-5 Codex vs grok-4-20-reasoning

Compare GPT-5 Codex (OpenAI) and grok-4-20-reasoning (X Ai) by price, context, capabilities, and latency.

Estimate costAll comparisons

Which should you pick?

  • Price: grok-4-20-reasoning is cheaper ($1.25 / 1M tokens input / $2.50 / 1M tokens output) vs GPT-5 Codex ($1.25 / 1M tokens input / $10 / 1M tokens output).
  • Context: GPT-5 Codex has the larger context window (400k tokens).

Side by side

GPT-5 Codex vs grok-4-20-reasoning — full comparison

Compare price, provider, context, capabilities, latency, and source basis.

ModelProviderInputOutputContextCapabilitiesBest forLatencyStatusSource
GPT-5 Codexopenai/gpt-5-codexOpenAI$1.25 / 1M tokens$10 / 1M tokens400k
Streaming
General chat via OpenAI, API workloads1780-3306msCatalogPlatform curated
grok-4-20-reasoningx-ai/grok-4.20-reasoningX Ai$1.25 / 1M tokens$2.50 / 1M tokens256k
Streaming
General chat via X Ai, API workloads2338-4154msCatalogPlatform curated

FAQ

GPT-5 Codex vs grok-4-20-reasoning FAQ

Is GPT-5 Codex or grok-4-20-reasoning cheaper?

grok-4-20-reasoning is cheaper ($1.25 / 1M tokens input / $2.50 / 1M tokens output) vs GPT-5 Codex ($1.25 / 1M tokens input / $10 / 1M tokens output). Actual cost depends on your input/output token mix — estimate it with the pricing calculator.

Which has a larger context window, GPT-5 Codex or grok-4-20-reasoning?

GPT-5 Codex is larger (400k tokens) vs 256k tokens.

GPT-5 Codex vs grok-4-20-reasoning for High quality: which should I pick?

Both target High quality. Pick grok-4-20-reasoning to optimize cost, or GPT-5 Codex for the longer context window. Test both on real prompts before committing production traffic.

GPT-5 Codex detailsgrok-4-20-reasoning detailsPricing calculatorOpenAI-compatible quickstart