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Comparison · 2 models · Updated Nov 2, 2026

GPT-5.1 Codex mini vs Aion-3.0-Mini

GPT-5.1 Codex mini comes out ahead, 54 to 41 on our weighted score, and it is the cheaper option too.

  1. Our pick

    OpenAI

    GPT-5.1 Codex mini

    Released Nov 13, 2025

    54/100
    • ECI—
    • Price$0.25 / $2.00
    • Context400K
  2. Aion Labs

    Aion-3.0-Mini

    Released May 14, 2026

    41/100
    • ECI—
    • Price$0.70 / $1.40
    • Context131K
  3. Add a model

    Make it a three-way comparison.

01 — Verdict

GPT-5.1 Codex mini is our pick

GPT-5.1 Codex mini is the better all-round choice, scoring 54/100 against Aion-3.0-Mini (41). It leads on price, inputs & features and context window. The score weighs price 50%, inputs & features 30%, context window 20%. None of the shared benchmarks cover every model here yet, so capability is left out of this verdict.

  • CapabilityNot enough dataNo independent benchmark covers every model here yet
  • Lowest priceGPT-5.1 Codex miniGPT-5.1 Codex mini $0.688 · Aion-3.0-Mini $0.875 per 1M tokens (3:1 blend)
  • Longest contextGPT-5.1 Codex miniGPT-5.1 Codex mini 400,000 · Aion-3.0-Mini 131,072 tokens
  • Widest inputsGPT-5.1 Codex miniGPT-5.1 Codex mini: Text, Images · Aion-3.0-Mini: Text
  • Self-hostingNo open weightsBoth are available only through APIs
How the score is built
MeasureWeightGPT-5.1 Codex miniAion-3.0-Mini
Price50%5550
Inputs & features30%6035
Context window20%4425
Overall100%54/10041/100

Left out because at least one model lacks the data: capability. The remaining weights were rescaled.

02 — Side by side

Every spec in one table

Highlighted cells lead their row. Dashes mean the data is not published.

GPT-5.1 Codex mini vs Aion-3.0-Mini specifications side by side
SpecificationGPT-5.1 Codex miniOpenAIAion-3.0-MiniAion Labs
Capability
Capabilities Index (ECI)——
ECI rank——
Price per million tokens
Input$0.25 (best)$0.70
Output$2.00$1.40 (best)
Cached input——
Blended (3:1)$0.688 (best)$0.875
Long-context rateSame rateSame rate
Price sourceMedian of 16 providersMedian of 4 providers
Limits
Context window400,000 tokens (best)131,072 tokens
Max output128,000 tokens (best)32,768 tokens
Inputs and features
TextYesYes
ImagesYesNo
PDFsNoNo
AudioNoNo
VideoNoNo
ReasoningYesYes
Tool callingYesYes
Structured outputNoNo
Availability
WeightsProprietaryProprietary
API model ID——
API providers16 (best)4
ReleasedNov 13, 2025May 14, 2026
Knowledge cutoffSep 30, 2024—
03 — Cost

What would a month cost?

Enter your expected volume in millions of tokens. List prices only; caching and batch discounts would lower these.

  • GPT-5.1 Codex mini$6.50
  • Aion-3.0-Mini$9.80
04 — Questions

Which should you choose?

Which is better: GPT-5.1 Codex mini or Aion-3.0-Mini?

GPT-5.1 Codex mini is the better all-round choice, scoring 54/100 against Aion-3.0-Mini (41). It leads on price, inputs & features and context window. The score weighs price 50%, inputs & features 30%, context window 20%. None of the shared benchmarks cover every model here yet, so capability is left out of this verdict.

Which is cheaper, GPT-5.1 Codex mini or Aion-3.0-Mini?

GPT-5.1 Codex mini is cheaper at $0.25 input / $2.00 output per million tokens (median across 16 API providers). Aion-3.0-Mini costs $0.70 input / $1.40 output per million tokens (median across 4 API providers). At a typical mix of three input tokens to one output token, that is $0.688 per million tokens for GPT-5.1 Codex mini versus $0.875 for Aion-3.0-Mini (1.3× as much).

Which scores higher on benchmarks?

There is no independent benchmark that covers both models yet. GPT-5.1 Codex mini has not been scored yet and Aion-3.0-Mini has not been scored yet.

Which is better for coding?

There are no published SWE-bench Verified results for GPT-5.1 Codex mini and Aion-3.0-Mini yet, so there is no like-for-like coding score. Test both on a sample of your own tasks. Both support tool calling for agent workflows.

Which has the bigger context window?

GPT-5.1 Codex mini has the largest context window at 400,000 tokens, against 131,072 for Aion-3.0-Mini. Maximum output per response: GPT-5.1 Codex mini up to 128,000, Aion-3.0-Mini up to 32,768 tokens.

Which can read images, PDFs, audio or video?

GPT-5.1 Codex mini accepts text and images; Aion-3.0-Mini accepts text. GPT-5.1 Codex mini handles the widest range of inputs.

Are any of these open source?

No. GPT-5.1 Codex mini and Aion-3.0-Mini are proprietary and only available through APIs and apps.

Which is newer?

Aion-3.0-Mini is the newest, released May 14, 2026. GPT-5.1 Codex mini came out Nov 13, 2025. Knowledge cutoff: GPT-5.1 Codex mini Sep 30, 2024.

How do you decide the winner?

Each model gets a 0–100 score on capability (50%, independent benchmark results); price (25%, blended price per million tokens (3 input : 1 output), log scale); inputs & features (15%, image, PDF, audio and video input, tool calling, structured output and reasoning); context window (10%, maximum tokens per request, log scale). Dimensions missing for any model are dropped and the remaining weights rescaled, so every model is judged on the same evidence. Specs and prices come from public model listings and the labs’ own API pages; capability scores come from independent benchmark runs. Data updated Nov 2, 2026.