GPT Realtime 2 vs Grok 4.5
GPT Realtime 2 and Grok 4.5 are both current production-tier models. Grok 4.5 is meaningfully cheaper at $2 / $6 per 1M. Grok 4.5 has a 500k context window — about 4× the 128k of GPT Realtime 2. Grok 4.5 leads on coding, reasoning, general knowledge.
Specs side by side
| Metric | OpenAI GPT Realtime 2 | xAI Grok 4.5 |
|---|---|---|
| Input price (per 1M) | $4 | $2 |
| Output price (per 1M) | $24 | $6 |
| Context window | 128k tokens | 500k tokens |
| Speed tier | ultra | balanced |
| Open weights | No | No |
| EU region | Yes | No |
| Free tier | No | No |
| Prompt caching | No | Yes |
| Vision input | No | Yes |
| Extended thinking | No | Yes |
When to choose each
Choose GPT Realtime 2 if…
- Low latency matters (ultra vs balanced)
- EU data residency is required
- You need realtime speech-to-speech
Choose Grok 4.5 if…
- Cost is a priority ($2 / $6 per 1M vs $4 / $24 per 1M)
- You need 500k context (4× more than GPT Realtime 2)
- You need image input / vision
- Coding is central to your workload
- Reasoning is central to your workload
Benchmark delta
GPT Realtime 2 leads on
GPT Realtime 2 has no meaningful benchmark lead in this pair.
Grok 4.5 leads on
- Coding
- Reasoning
- General knowledge
- Long-context retrieval
- Instruction following
- Tool use
FAQ — GPT Realtime 2 vs Grok 4.5
GPT Realtime 2 vs Grok 4.5 — which is better?
GPT Realtime 2 and Grok 4.5 are both current production-tier models. Grok 4.5 is meaningfully cheaper at $2 / $6 per 1M. Grok 4.5 has a 500k context window — about 4× the 128k of GPT Realtime 2. Grok 4.5 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 2 pricing compare to Grok 4.5?
GPT Realtime 2 costs $4 / $24 per 1M vs Grok 4.5 at $2 / $6 per 1M. Grok 4.5 is cheaper on output tokens by roughly 300%. Both support prompt caching, which reduces effective cost by 80-90% on repeat system prompts.
Does GPT Realtime 2 or Grok 4.5 have the bigger context window?
Grok 4.5 has a 500k-token context window — 4× the 128k context of GPT Realtime 2. Enough for long reports and multi-document analysis.
Is there a free tier for GPT Realtime 2 or Grok 4.5?
GPT Realtime 2: no — Paid-only. Grok 4.5: no — X Premium / SuperGrok includes Grok web chat; API is paid.
Which is better for coding — GPT Realtime 2 or Grok 4.5?
Grok 4.5 leads on coding benchmarks (GPT Realtime 2: 78/100, Grok 4.5: 94/100). For production coding agents also weigh tool-use performance — GPT Realtime 2 scores 84, Grok 4.5 scores 92.