GPT-5.4 Mini (OpenAI) and o4 Mini (OpenAI) compared on the ModelCap Index, API price, context window, provider availability, weight access and every public benchmark board they share. Figures are the same ones shown on the live rankings; nothing here is a hidden score.
Snapshot as of 22 September 2026
As of 22 September 2026, GPT-5.4 Mini holds the stronger ModelCap Index position (#34 vs #107); o4 Mini is cheaper per output token ($4.40/1M vs $4.50/1M); and GPT-5.4 Mini offers the longer context window (400K vs 200K tokens).
Evidence: 4 public benchmark observations across 4 boards · 3 public benchmark observations across 3 boards. Prices are the lowest listed API offer per million tokens observed on the OpenRouter catalogue.
Benchmark scores: GPT-5.4 Mini vs o4 Mini
Public benchmark boards where GPT-5.4 Mini or o4 Mini has a published result
GPT-5.4 Mini ranks higher on the ModelCap Index as of 22 September 2026: #34 against #107. That is a capability ranking built from public benchmark evidence with published uncertainty; whether it is "better" for you also depends on price, context and where you can run it. Their published uncertainty intervals do not overlap, but the aggregate Index does not predict performance on every task; compare the relevant benchmark configurations before choosing.
Is GPT-5.4 Mini cheaper than o4 Mini?
o4 Mini is cheaper on output tokens: $4.40/1M against $4.50/1M. Input tokens are $0.75/1M for GPT-5.4 Mini and $1.10/1M for o4 Mini. Prices are the lowest listed API offer ModelCap observed, in USD per million tokens. For 1,000 requests with 2,000 input and 500 output tokens each (2M input + 0.5M output), the listed-rate estimate is $3.75 for GPT-5.4 Mini versus $4.40 for o4 Mini. GPT-5.4 Mini costs 14.8% less in this scenario. This excludes caching, batch discounts, prompt-length tiers, tool charges and retries; verify the selected endpoint before budgeting.
Which has the bigger context window, GPT-5.4 Mini or o4 Mini?
GPT-5.4 Mini has the larger context window: 400K tokens against 200K.
Which is better for coding, GPT-5.4 Mini or o4 Mini?
Arena coding: GPT-5.4 Mini 1496, o4 Mini 1433 — GPT-5.4 Mini leads.
Are GPT-5.4 Mini and o4 Mini open-weight models?
GPT-5.4 Mini: API only. o4 Mini: API only. Open weights mean the checkpoint can be downloaded and self-hosted under its licence; API-only models are available solely through hosted endpoints.
Where can I run GPT-5.4 Mini and o4 Mini?
ModelCap currently lists 2 API providers for GPT-5.4 Mini and 1 for o4 Mini, from the OpenRouter catalogue snapshot the site serves; each model page lists the providers and their prices.
How current is this GPT-5.4 Mini vs o4 Mini comparison?
Every figure comes from the sealed ModelCap dataset published 22 September 2026; the page re-renders within a minute of each data refresh, and the ModelCap Index positions are the same ones shown on the live rankings.