GPT-4o vs Grok 3: Detailed Comparison

Choosing between GPT-4o (OpenAI) and Grok 3 (xAI) comes down to three things: per-token pricing, context window, and which capability matters most for your workload. GPT-4o costs $2.50/M input vs $3.00/M for Grok 3; context windows are 128K vs 1.0M tokens. Detailed breakdown below.

Side-by-side specs

SpecGPT-4oGrok 3
ProviderOpenAIxAI
Released2024-05-132025-02-17
Input price $2.50/M $3.00/M
Output price $10.00/M $15.00/M
Cached input $1.2500/M
Context window 128K 1.0M
Max output 16K 16K
Modalities text image audio text image
Tokenizer o200k_base grok

Capability matrix

CapabilityGPT-4oGrok 3
function calling Yes Yes
json mode Yes Yes
vision Yes Yes
streaming Yes Yes
audio Yes No
realtime web No Yes

Benchmark comparison

Higher is better for all benchmarks shown.

BenchmarkCategoryGPT-4oGrok 3Δ
MMLU general 88.7
HumanEval coding 90.2
MMMU multimodal 69.1
GPQA Diamond reasoning 84.6
AIME 2025 math 93.3

Per-call cost on typical workloads

Workload (in/out tokens)GPT-4oGrok 3Cheaper by
Standard chat (1K / 500) $0.007500 $0.010500 GPT-4o by $0.003000
RAG (4K / 500) $0.015000 $0.019500 GPT-4o by $0.004500
Long doc (20K / 1K) $0.060000 $0.075000 GPT-4o by $0.015000
Very long context (100K / 2K) $0.265000 $0.322500 GPT-4o by $0.057500

When to choose GPT-4o over Grok 3

  • Per-token input cost is 17% lower — meaningful for high-volume workloads.
  • Supports audio — Grok 3 does not.

When to choose Grok 3 over GPT-4o

  • Larger context window (1.0M vs 128K).
  • Supports realtime web — GPT-4o does not.

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