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Head-to-head comparison

GPT-5.4 Mini vs GPT-5.5

GPT-5.4 Mini (OpenAI) and GPT-5.5 (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-5.5 holds the stronger ModelCap Index position (#13 vs #34); GPT-5.4 Mini is 6.7× cheaper per output token ($4.50/1M vs $30.00/1M); and GPT-5.5 offers the longer context window (1M vs 400K tokens).

Which should you choose?

Choose GPT-5.4 Mini if…

  • API cost matters — $4.50/1M output tokens against $30.00/1M, about 6.7× cheaper.
  • your workload is prompt-heavy — input tokens cost $0.75/1M against $5.00/1M.

Choose GPT-5.5 if…

  • you want the stronger overall ModelCap Index position — #13 against #34 (82.5 vs 71.9 points).
  • you need the longer context window — 1M tokens against 400K.
  • you want provider choice — 3 listed API providers against 2.
  • Arena coding is your yardstick — 1520 against 1496.
  • ARC-AGI-2 is your yardstick — 85.0% against 18.9%.
  • AA Intelligence Index is your yardstick — 38.4 against 24.1.
  • AA τ²-Bench Telecom is your yardstick — 93.9% against 83.3%.
  • AA Humanity's Last Exam is your yardstick — 45.8% against 28.1%.
  • you want the more recently listed model — GPT-5.5 was listed 24 April 2026, GPT-5.4 Mini 17 March 2026.

GPT-5.4 Mini vs GPT-5.5: specs, pricing and context

Specification comparison of GPT-5.4 Mini and GPT-5.5
FieldGPT-5.4 MiniOpenAIGPT-5.5OpenAI
ModelCap Index position#34#13
Index score71.982.5
EvidenceMeasuredMeasured
Input price / 1M tokens$0.75$5.00
Output price / 1M tokens$4.50$30.00
Context window400K tokens1M tokens
Max output tokens128K128K
API providers listed23
Weight accessAPI onlyAPI only
Input modalitiesFile, Image, TextFile, Image, Text
First listed17 March 202624 April 2026
PublisherOpenAIOpenAI

Evidence: 4 public benchmark observations across 4 boards · 7 public benchmark observations across 7 boards. Prices are the lowest listed API offer per million tokens observed on the OpenRouter catalogue.

Benchmark scores: GPT-5.4 Mini vs GPT-5.5

Public benchmark boards where GPT-5.4 Mini or GPT-5.5 has a published result
BoardGPT-5.4 MiniGPT-5.5Leads
Arena codingArena (LMArena)14961490–1502High15201514–1526HighGPT-5.5
LMArena AgentLMArena—5.0%4.1%–6.0%X-HighOnly one result
ARC-AGI-2ARC Prize Foundation18.9%X-High85.0%X-HighGPT-5.5
ARC-AGI-3ARC Prize Foundation—0.4%HighOnly one result
AA Intelligence IndexArtificial Analysis24.1intelligence-index:v4.3:xhigh38.4intelligence-index:v4.3:xhighGPT-5.5
AA τ²-Bench TelecomArtificial Analysis83.3%tau2:telecom:dual-control:pass-at-1:3-repeats:source-model="GPT-5.4 mini (xhigh)":reasoning=true93.9%tau2:telecom:dual-control:pass-at-1:3-repeats:source-model="GPT-5.5 (xhigh)":reasoning=trueGPT-5.5
AA Humanity's Last ExamArtificial Analysis28.1%hle:may-2025:text-only-2158:no-tools:pass-at-1:source-model="GPT-5.4 mini (xhigh)":reasoning=true45.8%hle:may-2025:text-only-2158:no-tools:pass-at-1:source-model="GPT-5.5 (xhigh)":reasoning=trueGPT-5.5
Terminal-Bench 2.1 Terminus 2Terminal-Bench—78.0X-HighOnly one result
WildClawBench OpenClawWildClawBench—58.2Only one result

Scores are the sources' own published figures for each model's best evaluated configuration; ModelCap never re-runs a benchmark.

Want a different pairing? Open the interactive comparison tool to swap either model for any current ranked language model.

GPT-5.4 Mini vs GPT-5.5: common questions

Is GPT-5.4 Mini better than GPT-5.5?

GPT-5.5 ranks higher on the ModelCap Index as of 22 September 2026: #13 against #34. 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 overlap, so the rank difference alone does not establish a reliable capability advantage for your workload.

Is GPT-5.4 Mini cheaper than GPT-5.5?

GPT-5.4 Mini is cheaper on output tokens: $4.50/1M against $30.00/1M. Input tokens are $0.75/1M for GPT-5.4 Mini and $5.00/1M for GPT-5.5. 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 $25.00 for GPT-5.5. GPT-5.4 Mini costs 85.0% 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 GPT-5.5?

GPT-5.5 has the larger context window: 1M tokens against 400K.

Which is better for coding, GPT-5.4 Mini or GPT-5.5?

Arena coding: GPT-5.4 Mini 1496, GPT-5.5 1520 — GPT-5.5 leads.

Are GPT-5.4 Mini and GPT-5.5 open-weight models?

GPT-5.4 Mini: API only. GPT-5.5: 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 GPT-5.5?

ModelCap currently lists 2 API providers for GPT-5.4 Mini and 3 for GPT-5.5, 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 GPT-5.5 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.

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