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Comparison · 2 models · Updated Oct 4, 2026

Claude Sonnet 4.5 vs GPT-5.4 mini

GPT-5.4 mini comes out ahead, 63 to 55 on our weighted score, and it is the cheaper option too.

  1. Anthropic

    Claude Sonnet 4.5

    Released Sep 29, 2025

    55/100
    • ECI146.8
    • Price$3.00 / $15.00
    • Context200K
    Full specs Remove Claude Sonnet 4.5
  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 Claude Sonnet 4.5 (55). It leads on capability, price and context window. Claude Sonnet 4.5 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 · Claude Sonnet 4.5 146.8
  • Lowest priceGPT-5.4 miniGPT-5.4 mini $1.69 · Claude Sonnet 4.5 $6.00 per 1M tokens (3:1 blend)
  • Longest contextGPT-5.4 miniGPT-5.4 mini 400,000 · Claude Sonnet 4.5 200,000 tokens
  • Widest inputsClaude Sonnet 4.5Claude Sonnet 4.5: Text, Images, PDFs · GPT-5.4 mini: Text, Images
  • Self-hostingNo open weightsBoth are available only through APIs
How the score is built
MeasureWeightClaude Sonnet 4.5GPT-5.4 mini
CapabilityCapabilities Index (ECI)50%7477
Price25%1339
Inputs & features15%8070
Context window10%3244
Overall100%55/10063/100
02 — Side by side

Every spec in one table

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

Claude Sonnet 4.5 vs GPT-5.4 mini specifications side by side
SpecificationClaude Sonnet 4.5AnthropicGPT-5.4 miniOpenAI
Capability
Capabilities Index (ECI)146.8148.8 (best)
ECI rank#64 of 148#56 of 148 (best)
GPQA DiamondGraduate-level science questions82.3%86.9% (best)
FrontierMath Tiers 1–3Research-level mathematics23.9%51.2% (best)
OTIS Mock AIME 2024–2025Competition mathematics77.8%88.9% (best)
SWE-bench VerifiedFixing real GitHub issues71.3%—
SimpleQA VerifiedShort factual questions30.7% (best)29.4%
Price per million tokens
Input$3.00$0.75 (best)
Output$15.00$4.50 (best)
Cached input$0.30$0.075 (best)
Blended (3:1)$6.00$1.69 (best)
Long-context rateSame rateSame rate
Price sourceOfficial Anthropic APIOfficial OpenAI API
Limits
Context window200,000 tokens400,000 tokens (best)
Max output64,000 tokens128,000 tokens (best)
Inputs and features
TextYesYes
ImagesYesYes
PDFsYesNo
AudioNoNo
VideoNoNo
ReasoningYesYeslow · medium · high · xhigh
Tool callingYesYes
Structured outputYesYes
Availability
WeightsProprietaryProprietary
API model IDclaude-sonnet-4-5gpt-5.4-mini
API providers2829 (best)
ReleasedSep 29, 2025Mar 17, 2026
Knowledge cutoffJul 31, 2025Aug 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.

  • Claude Sonnet 4.5$60.00
  • GPT-5.4 mini$16.50
04 — Questions

Which should you choose?

Which is better: Claude Sonnet 4.5 or GPT-5.4 mini?

GPT-5.4 mini is the better all-round choice, scoring 63/100 against Claude Sonnet 4.5 (55). It leads on capability, price and context window. Claude Sonnet 4.5 wins on inputs & features. The score weighs capability 50%, price 25%, inputs & features 15%, context window 10%.

Which is cheaper, Claude Sonnet 4.5 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). Claude Sonnet 4.5 costs $3.00 input / $15.00 output per million tokens (official Anthropic 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 $6.00 for Claude Sonnet 4.5 (3.6× 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 Claude Sonnet 4.5 146.8 (#64 of 148). The confidence ranges of the top two overlap (147.1–150.5 vs 145.3–148.5), so treat the gap as small. On individual benchmarks: GPQA Diamond — GPT-5.4 mini 86.9%, Claude Sonnet 4.5 82.3%; FrontierMath Tiers 1–3 — GPT-5.4 mini 51.2%, Claude Sonnet 4.5 23.9%; OTIS Mock AIME 2024–2025 — GPT-5.4 mini 88.9%, Claude Sonnet 4.5 77.8%; SimpleQA Verified — Claude Sonnet 4.5 30.7%, 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 Claude Sonnet 4.5. Maximum output per response: Claude Sonnet 4.5 up to 64,000, GPT-5.4 mini up to 128,000 tokens.

Which can read images, PDFs, audio or video?

Claude Sonnet 4.5 accepts text, images and PDFs; GPT-5.4 mini accepts text and images. Claude Sonnet 4.5 handles the widest range of inputs.

Are any of these open source?

No. Claude Sonnet 4.5 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. Claude Sonnet 4.5 came out Sep 29, 2025. Knowledge cutoff: Claude Sonnet 4.5 Jul 31, 2025, 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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