Skip to content
ModelCap

Head-to-head comparison

GPT-5.6 Terra vs o4 Mini

GPT-5.6 Terra (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-5.6 Terra holds the stronger ModelCap Index position (#21 vs #106); o4 Mini is 2.7× cheaper per output token ($4.40/1M vs $12.00/1M); and GPT-5.6 Terra offers the longer context window (1M vs 200K tokens).

Which should you choose?

Choose GPT-5.6 Terra if…

  • you want the stronger overall ModelCap Index position — #21 against #106 (79.7 vs 51.6 points).
  • you need the longer context window — 1M tokens against 200K.
  • you want provider choice — 3 listed API providers against 1.
  • Arena coding is your yardstick — 1518 against 1433.
  • ARC-AGI-2 is your yardstick — 83.9% against 6.1%.
  • AA τ²-Bench Telecom is your yardstick — 86.3% against 55.6%.
  • AA Humanity's Last Exam is your yardstick — 42.9% against 16.5%.
  • you want the more recently listed model — GPT-5.6 Terra was listed 9 July 2026, o4 Mini 16 April 2025.

Choose o4 Mini if…

  • API cost matters — $4.40/1M output tokens against $12.00/1M, about 2.7× cheaper.
  • your workload is prompt-heavy — input tokens cost $1.10/1M against $2.00/1M.

GPT-5.6 Terra vs o4 Mini: specs, pricing and context

Specification comparison of GPT-5.6 Terra and o4 Mini
FieldGPT-5.6 TerraOpenAIo4 MiniOpenAI
ModelCap Index position#21#106
Index score79.751.6
EvidenceMeasuredMeasured
Input price / 1M tokens$2.00$1.10
Output price / 1M tokens$12.00$4.40
Context window1M tokens200K tokens
Max output tokens128K100K
API providers listed31
Weight accessAPI onlyAPI only
Input modalitiesFile, Image, TextImage, Text, File
First listed9 July 202616 April 2025
PublisherOpenAIOpenAI

Evidence: 6 public benchmark observations across 6 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-5.6 Terra vs o4 Mini

Public benchmark boards where GPT-5.6 Terra or o4 Mini has a published result
BoardGPT-5.6 Terrao4 MiniLeads
Arena codingArena (LMArena)15181510–1525X-High14331426–1440GPT-5.6 Terra
LMArena AgentLMArena1.4%0.3%–2.6%X-High—Only one result
ARC-AGI-2ARC Prize Foundation83.9%Max6.1%HighGPT-5.6 Terra
ARC-AGI-3ARC Prize Foundation0.8%Max—Only one result
SWE-benchSWE-bench (Princeton / SWE-agent team)—45.0%Only one result
BFCL V4UC Berkeley (Gorilla)—53.2Function callingOnly one result
AA Intelligence IndexArtificial Analysis42.1intelligence-index:v4.3:max—Only one result
AA τ²-Bench TelecomArtificial Analysis86.3%tau2:telecom:dual-control:pass-at-1:3-repeats:source-model="GPT-5.6 Terra (max)":reasoning=true55.6%tau2:telecom:dual-control:pass-at-1:3-repeats:source-model="o4-mini (high)":reasoning=trueGPT-5.6 Terra
AA Humanity's Last ExamArtificial Analysis42.9%hle:may-2025:text-only-2158:no-tools:pass-at-1:source-model="GPT-5.6 Terra (max)":reasoning=true16.5%hle:may-2025:text-only-2158:no-tools:pass-at-1:source-model="o4-mini (high)":reasoning=trueGPT-5.6 Terra
Terminal-Bench 4.0Terminal-Bench (Laude Institute)21.5%18.3%–24.8%Codex · Max—Only 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-5.6 Terra vs o4 Mini: common questions

Is GPT-5.6 Terra better than o4 Mini?

GPT-5.6 Terra ranks higher on the ModelCap Index as of 22 September 2026: #21 against #106. 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-5.6 Terra cheaper than o4 Mini?

o4 Mini is cheaper on output tokens: $4.40/1M against $12.00/1M. Input tokens are $2.00/1M for GPT-5.6 Terra 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 $10.00 for GPT-5.6 Terra versus $4.40 for o4 Mini. o4 Mini costs 56.0% 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-5.6 Terra or o4 Mini?

GPT-5.6 Terra has the larger context window: 1M tokens against 200K.

Which is better for coding, GPT-5.6 Terra or o4 Mini?

Arena coding: GPT-5.6 Terra 1518, o4 Mini 1433 — GPT-5.6 Terra leads.

Are GPT-5.6 Terra and o4 Mini open-weight models?

GPT-5.6 Terra: 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-5.6 Terra and o4 Mini?

ModelCap currently lists 3 API providers for GPT-5.6 Terra 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-5.6 Terra 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.

Explore further