GPT-5.5 vs o4-mini
GPT-5.5 and o4-mini are both current openai production-tier models. o4-mini is meaningfully cheaper at $1.1 / $4.4 per 1M. GPT-5.5 has a 1.1M context window — about 5× the 200k of o4-mini. GPT-5.5 leads on general knowledge, long-context retrieval, instruction following.
Specs side by side
| Metric | OpenAI GPT-5.5 | OpenAI o4-mini |
|---|---|---|
| Input price (per 1M) | $5 | $1.1 |
| Output price (per 1M) | $30 | $4.4 |
| Context window | 1.1M tokens | 200k tokens |
| Speed tier | balanced | slow |
| Open weights | No | No |
| EU region | Yes | Yes |
| Free tier | No | No |
| Prompt caching | Yes | Yes |
| Vision input | Yes | Yes |
| Extended thinking | Yes | Yes |
When to choose each
Choose GPT-5.5 if…
- You need 1.1M context (5× more than o4-mini)
- You need realtime speech-to-speech
- General knowledge is central to your workload
- Long-context retrieval is central to your workload
Choose o4-mini if…
- Cost is a priority ($1.1 / $4.4 per 1M vs $5 / $30 per 1M)
Benchmark delta
GPT-5.5 leads on
- General knowledge
- Long-context retrieval
- Instruction following
- Multilingual
- Vision
- Tool use
o4-mini leads on
o4-mini has no meaningful benchmark lead in this pair.
FAQ — GPT-5.5 vs o4-mini
GPT-5.5 vs o4-mini — which is better?
GPT-5.5 and o4-mini are both current openai production-tier models. o4-mini is meaningfully cheaper at $1.1 / $4.4 per 1M. GPT-5.5 has a 1.1M context window — about 5× the 200k of o4-mini. GPT-5.5 leads on general knowledge, long-context retrieval, instruction following. The right pick depends on your use case — see "When to choose each" above for a data-driven decision.
How does GPT-5.5 pricing compare to o4-mini?
GPT-5.5 costs $5 / $30 per 1M vs o4-mini at $1.1 / $4.4 per 1M. o4-mini is cheaper on output tokens by roughly 582%. Both support prompt caching, which reduces effective cost by 80-90% on repeat system prompts.
Does GPT-5.5 or o4-mini have the bigger context window?
GPT-5.5 has a 1.1M-token context window — 5× the 200k context of o4-mini. Enough for entire codebases, books, or multi-document RAG.
Is there a free tier for GPT-5.5 or o4-mini?
GPT-5.5: no — Paid-only — no free API tier; available via ChatGPT Plus/Pro. o4-mini: no — Paid-only.
Which is better for coding — GPT-5.5 or o4-mini?
GPT-5.5 leads on coding benchmarks (GPT-5.5: 95/100, o4-mini: 92/100). For production coding agents also weigh tool-use performance — GPT-5.5 scores 94, o4-mini scores 88.