ZMIME
Comparison · 2 models · Updated Oct 4, 2026

GPT-5.1 vs GPT-5.4 mini

GPT-5.4 mini comes out ahead, 63 to 60 on our weighted score, and it is the cheaper option too.

  1. OpenAI

    GPT-5.1

    Released Nov 13, 2025

    60/100
    • ECI149.7
    • Price$1.25 / $10.00
    • Context400K
    Full specs Remove GPT-5.1
  2. Our pick

    OpenAI

    GPT-5.4 mini

    Released Mar 17, 2026

    63/100
    • ECI148.8
    • Price$0.75 / $4.50
    • Context400K
    Full specs Remove GPT-5.4 mini

  3. Add a model

    Make it a three-way comparison.

01 — Verdict

GPT-5.4 mini is our pick

GPT-5.4 mini is the better all-round choice, scoring 63/100 against GPT-5.1 (60). It leads on price. The score weighs capability 50%, price 25%, inputs & features 15%, context window 10%.

  • CapabilityGPT-5.1Capabilities Index (ECI): GPT-5.1 149.7 · GPT-5.4 mini 148.8
  • Lowest priceGPT-5.4 miniGPT-5.4 mini $1.69 · GPT-5.1 $3.44 per 1M tokens (3:1 blend)
  • Longest contextAbout the sameGPT-5.1 400,000 · GPT-5.4 mini 400,000 tokens
  • Widest inputsSame inputsGPT-5.1: Text, Images · GPT-5.4 mini: Text, Images
  • Self-hostingNo open weightsBoth are available only through APIs
How the score is built
MeasureWeightGPT-5.1GPT-5.4 mini
CapabilityCapabilities Index (ECI)50%7877
Price25%2439
Inputs & features15%7070
Context window10%4444
Overall100%60/10063/100
02 — Side by side

Every spec in one table

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

GPT-5.1 vs GPT-5.4 mini specifications side by side
SpecificationGPT-5.1OpenAIGPT-5.4 miniOpenAI
Capability
Capabilities Index (ECI)149.7 (best)148.8
ECI rank#52 of 148 (best)#56 of 148
GPQA DiamondGraduate-level science questions87.6% (best)86.9%
FrontierMath Tiers 1–3Research-level mathematics—51.2%
OTIS Mock AIME 2024–2025Competition mathematics88.6%88.9% (best)
SWE-bench VerifiedFixing real GitHub issues68.0%—
SimpleQA VerifiedShort factual questions48.0% (best)29.4%
Price per million tokens
Input$1.25$0.75 (best)
Output$10.00$4.50 (best)
Cached input$0.125$0.075 (best)
Blended (3:1)$3.44$1.69 (best)
Long-context rateSame rateSame rate
Price sourceOfficial OpenAI APIOfficial OpenAI API
Limits
Context window400,000 tokens400,000 tokens
Max output128,000 tokens128,000 tokens
Inputs and features
TextYesYes
ImagesYesYes
PDFsNoNo
AudioNoNo
VideoNoNo
ReasoningYeslow · medium · highYeslow · medium · high · xhigh
Tool callingYesYes
Structured outputYesYes
Availability
WeightsProprietaryProprietary
API model IDgpt-5.1gpt-5.4-mini
API providers2129 (best)
ReleasedNov 13, 2025Mar 17, 2026
Knowledge cutoffSep 30, 2024Aug 31, 2025
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$32.50
  • GPT-5.4 mini$16.50
04 — Questions

Which should you choose?

Which is better: GPT-5.1 or GPT-5.4 mini?

GPT-5.4 mini is the better all-round choice, scoring 63/100 against GPT-5.1 (60). It leads on price. The score weighs capability 50%, price 25%, inputs & features 15%, context window 10%.

Which is cheaper, GPT-5.1 or GPT-5.4 mini?

GPT-5.4 mini is cheaper at $0.75 input / $4.50 output per million tokens (official OpenAI API price). GPT-5.1 costs $1.25 input / $10.00 output per million tokens (official OpenAI API price). At a typical mix of three input tokens to one output token, that is $1.69 per million tokens for GPT-5.4 mini versus $3.44 for GPT-5.1 (2× as much).

Which scores higher on benchmarks?

GPT-5.1 scores higher on the Capabilities Index (ECI): GPT-5.1 149.7 (#52 of 148) and GPT-5.4 mini 148.8 (#56 of 148). The confidence ranges of the top two overlap (148.3–151.1 vs 147.1–150.5), so treat the gap as small. On individual benchmarks: GPQA Diamond — GPT-5.1 87.6%, GPT-5.4 mini 86.9%; OTIS Mock AIME 2024–2025 — GPT-5.4 mini 88.9%, GPT-5.1 88.6%; SimpleQA Verified — GPT-5.1 48.0%, GPT-5.4 mini 29.4%.

Which is better for coding?

There are no published SWE-bench Verified results for GPT-5.4 mini yet, so there is no like-for-like coding score. On overall capability, GPT-5.1 leads, which tends to carry over to coding, but test on your own codebase. Both support tool calling for agent workflows.

Which has the bigger context window?

GPT-5.1 and GPT-5.4 mini share the same 400,000-token context window. Maximum output per response: GPT-5.1 up to 128,000, GPT-5.4 mini up to 128,000 tokens.

Which can read images, PDFs, audio or video?

GPT-5.1 accepts text and images; GPT-5.4 mini accepts text and images. They handle the same number of input types.

Are any of these open source?

No. GPT-5.1 and GPT-5.4 mini are proprietary and only available through APIs and apps.

Which is newer?

GPT-5.4 mini is the newest, released Mar 17, 2026. GPT-5.1 came out Nov 13, 2025. Knowledge cutoff: GPT-5.1 Sep 30, 2024, GPT-5.4 mini Aug 31, 2025.

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 Oct 4, 2026.

05 — Keep comparing

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