GPT-5.4 Mini vs GPT Realtime

GPT-5.4 Mini and GPT Realtime are both current openai production-tier models. GPT-5.4 Mini is meaningfully cheaper at $0.75 / $4.5 per 1M. GPT-5.4 Mini has a 400k context window — about 3× the 128k of GPT Realtime. GPT-5.4 Mini leads on coding, reasoning, long-context retrieval.

Specs side by side

Metric
OpenAI
GPT-5.4 Mini
OpenAI
GPT Realtime
Input price (per 1M)$0.75$4
Output price (per 1M)$4.5$16
Context window400k tokens128k tokens
Speed tierfastultra
Open weightsNoNo
EU regionYesYes
Free tierNoNo
Prompt cachingYesNo
Vision inputYesNo
Extended thinkingYesNo

When to choose each

OpenAI

Choose GPT-5.4 Mini if…

  • Cost is a priority ($0.75 / $4.5 per 1M vs $4 / $16 per 1M)
  • You need 400k context (3× more than GPT Realtime)
  • HIPAA eligibility is required
  • You need image input / vision
  • Coding is central to your workload
  • Reasoning is central to your workload
OpenAI

Choose GPT Realtime if…

  • You need realtime speech-to-speech

Benchmark delta

GPT-5.4 Mini leads on

  • Coding
  • Reasoning
  • Long-context retrieval

GPT Realtime leads on

GPT Realtime has no meaningful benchmark lead in this pair.

FAQ — GPT-5.4 Mini vs GPT Realtime

GPT-5.4 Mini vs GPT Realtime — which is better?

GPT-5.4 Mini and GPT Realtime are both current openai production-tier models. GPT-5.4 Mini is meaningfully cheaper at $0.75 / $4.5 per 1M. GPT-5.4 Mini has a 400k context window — about 3× the 128k of GPT Realtime. GPT-5.4 Mini leads on coding, reasoning, long-context retrieval. The right pick depends on your use case — see "When to choose each" above for a data-driven decision.

How does GPT-5.4 Mini pricing compare to GPT Realtime?

GPT-5.4 Mini costs $0.75 / $4.5 per 1M vs GPT Realtime at $4 / $16 per 1M. GPT-5.4 Mini is cheaper on output tokens by roughly 256%. Both support prompt caching, which reduces effective cost by 80-90% on repeat system prompts.

Does GPT-5.4 Mini or GPT Realtime have the bigger context window?

GPT-5.4 Mini has a 400k-token context window — 3× the 128k context of GPT Realtime. Enough for long reports and multi-document analysis.

Is there a free tier for GPT-5.4 Mini or GPT Realtime?

GPT-5.4 Mini: no — Near-free at $0.75/$4.50 per 1M; starter credits only. GPT Realtime: no — Paid-only.

Which is better for coding — GPT-5.4 Mini or GPT Realtime?

GPT-5.4 Mini leads on coding benchmarks (GPT-5.4 Mini: 84/100, GPT Realtime: 78/100). For production coding agents also weigh tool-use performance — GPT-5.4 Mini scores 86, GPT Realtime scores 84.