GPT Realtime vs Grok 4.3

GPT Realtime and Grok 4.3 are both current production-tier models. Grok 4.3 is meaningfully cheaper at $1.25 / $2.5 per 1M. Grok 4.3 leads on coding, reasoning, general knowledge.

Specs side by side

Metric
OpenAI
GPT Realtime
xAI
Grok 4.3
Input price (per 1M)$4$1.25
Output price (per 1M)$16$2.5
Context window128k tokens256k tokens
Speed tierultrabalanced
Open weightsNoNo
EU regionYesNo
Free tierNoNo
Prompt cachingNoYes
Vision inputNoYes
Extended thinkingNoYes

When to choose each

OpenAI

Choose GPT Realtime if…

  • Low latency matters (ultra vs balanced)
  • EU data residency is required
  • You need realtime speech-to-speech
xAI

Choose Grok 4.3 if…

  • Cost is a priority ($1.25 / $2.5 per 1M vs $4 / $16 per 1M)
  • You need 256k context (2× more than GPT Realtime)
  • You need image input / vision
  • Coding is central to your workload
  • Reasoning is central to your workload

Benchmark delta

GPT Realtime leads on

GPT Realtime has no meaningful benchmark lead in this pair.

Grok 4.3 leads on

  • Coding
  • Reasoning
  • General knowledge
  • Long-context retrieval
  • Instruction following
  • Tool use

FAQ — GPT Realtime vs Grok 4.3

GPT Realtime vs Grok 4.3 — which is better?

GPT Realtime and Grok 4.3 are both current production-tier models. Grok 4.3 is meaningfully cheaper at $1.25 / $2.5 per 1M. Grok 4.3 leads on coding, reasoning, general knowledge. The right pick depends on your use case — see "When to choose each" above for a data-driven decision.

How does GPT Realtime pricing compare to Grok 4.3?

GPT Realtime costs $4 / $16 per 1M vs Grok 4.3 at $1.25 / $2.5 per 1M. Grok 4.3 is cheaper on output tokens by roughly 540%. Both support prompt caching, which reduces effective cost by 80-90% on repeat system prompts.

Does GPT Realtime or Grok 4.3 have the bigger context window?

Grok 4.3 has a 256k-token context window — 2× the 128k context of GPT Realtime. Enough for long reports and multi-document analysis.

Is there a free tier for GPT Realtime or Grok 4.3?

GPT Realtime: no — Paid-only. Grok 4.3: no — X Premium / SuperGrok includes Grok web chat; API is paid.

Which is better for coding — GPT Realtime or Grok 4.3?

Grok 4.3 leads on coding benchmarks (GPT Realtime: 78/100, Grok 4.3: 91/100). For production coding agents also weigh tool-use performance — GPT Realtime scores 84, Grok 4.3 scores 90.