ZMIME
Comparison · 2 models · Updated Oct 4, 2026

GPT-5.4 mini vs o3

GPT-5.4 mini comes out ahead, 63 to 58 on our weighted score, and it is the cheaper option too.

  1. 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

  2. OpenAI

    o3

    Released Apr 16, 2025

    58/100
    • ECI146.9
    • Price$2.00 / $8.00
    • Context200K
    Full specs Remove o3

  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 o3 (58). It leads on capability, price and context window. o3 wins on inputs & features. The score weighs capability 50%, price 25%, inputs & features 15%, context window 10%.

  • CapabilityGPT-5.4 miniCapabilities Index (ECI): GPT-5.4 mini 148.8 · o3 146.9
  • Lowest priceGPT-5.4 miniGPT-5.4 mini $1.69 · o3 $3.50 per 1M tokens (3:1 blend)
  • Longest contextGPT-5.4 miniGPT-5.4 mini 400,000 · o3 200,000 tokens
  • Widest inputso3GPT-5.4 mini: Text, Images · o3: Text, Images, PDFs
  • Self-hostingNo open weightsBoth are available only through APIs
How the score is built
MeasureWeightGPT-5.4 minio3
CapabilityCapabilities Index (ECI)50%7774
Price25%3924
Inputs & features15%7080
Context window10%4432
Overall100%63/10058/100
02 — Side by side

Every spec in one table

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

GPT-5.4 mini vs o3 specifications side by side
SpecificationGPT-5.4 miniOpenAIo3OpenAI
Capability
Capabilities Index (ECI)148.8 (best)146.9
ECI rank#56 of 148 (best)#63 of 148
GPQA DiamondGraduate-level science questions86.9% (best)81.8%
FrontierMath Tiers 1–3Research-level mathematics51.2% (best)33.3%
OTIS Mock AIME 2024–2025Competition mathematics88.9% (best)84.4%
SWE-bench VerifiedFixing real GitHub issues—62.3%
SimpleQA VerifiedShort factual questions29.4%49.4% (best)
Price per million tokens
Input$0.75 (best)$2.00
Output$4.50 (best)$8.00
Cached input$0.075 (best)$0.50
Blended (3:1)$1.69 (best)$3.50
Long-context rateSame rateSame rate
Price sourceOfficial OpenAI APIOfficial OpenAI API
Limits
Context window400,000 tokens (best)200,000 tokens
Max output128,000 tokens (best)100,000 tokens
Inputs and features
TextYesYes
ImagesYesYes
PDFsNoYes
AudioNoNo
VideoNoNo
ReasoningYeslow · medium · high · xhighYeslow · medium · high
Tool callingYesYes
Structured outputYesYes
Availability
WeightsProprietaryProprietary
API model IDgpt-5.4-minio3
API providers29 (best)18
ReleasedMar 17, 2026Apr 16, 2025
Knowledge cutoffAug 31, 2025May 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-5.4 mini$16.50
  • o3$36.00
04 — Questions

Which should you choose?

Which is better: GPT-5.4 mini or o3?

GPT-5.4 mini is the better all-round choice, scoring 63/100 against o3 (58). It leads on capability, price and context window. o3 wins on inputs & features. The score weighs capability 50%, price 25%, inputs & features 15%, context window 10%.

Which is cheaper, GPT-5.4 mini or o3?

GPT-5.4 mini is cheaper at $0.75 input / $4.50 output per million tokens (official OpenAI API price). o3 costs $2.00 input / $8.00 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 $3.50 for o3 (2.1× as much).

Which scores higher on benchmarks?

GPT-5.4 mini scores higher on the Capabilities Index (ECI): GPT-5.4 mini 148.8 (#56 of 148) and o3 146.9 (#63 of 148). The confidence ranges of the top two overlap (147.1–150.5 vs 144.9–148.6), so treat the gap as small. On individual benchmarks: GPQA Diamond — GPT-5.4 mini 86.9%, o3 81.8%; FrontierMath Tiers 1–3 — GPT-5.4 mini 51.2%, o3 33.3%; OTIS Mock AIME 2024–2025 — GPT-5.4 mini 88.9%, o3 84.4%; SimpleQA Verified — o3 49.4%, 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-5.4 mini 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-5.4 mini has the largest context window at 400,000 tokens, against 200,000 for o3. Maximum output per response: GPT-5.4 mini up to 128,000, o3 up to 100,000 tokens.

Which can read images, PDFs, audio or video?

GPT-5.4 mini accepts text and images; o3 accepts text, images and PDFs. o3 handles the widest range of inputs.

Are any of these open source?

No. GPT-5.4 mini and o3 are proprietary and only available through APIs and apps.

Which is newer?

GPT-5.4 mini is the newest, released Mar 17, 2026. o3 came out Apr 16, 2025. Knowledge cutoff: GPT-5.4 mini Aug 31, 2025, o3 May 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 Oct 4, 2026.

05 — Keep comparing

Related comparisons