ZMIME
Comparison · 3 models · Updated Oct 4, 2026

GPT-5.4 mini vs Claude Opus 4.5 vs Grok 4.3

Grok 4.3 comes out ahead, 67 to 63 and 55 on our weighted score, and it is the cheaper option too.

  1. OpenAI

    GPT-5.4 mini

    Released Mar 17, 2026

    63/100
    • ECI148.8
    • Price$0.75 / $4.50
    • Context400K
  2. Anthropic

    Claude Opus 4.5

    Released Nov 24, 2025

    55/100
    • ECI150.1
    • Price$5.00 / $25.00
    • Context200K
  3. Our pick

    xAI

    Grok 4.3

    Released Apr 17, 2026

    67/100
    • ECI149.2
    • Price$1.25 / $2.50
    • Context1M
01 — Verdict

Grok 4.3 is our pick

Grok 4.3 is the better all-round choice, scoring 67/100 against GPT-5.4 mini (63) and Claude Opus 4.5 (55). It leads on context window. The score weighs capability 50%, price 25%, inputs & features 15%, context window 10%.

  • CapabilityClaude Opus 4.5Capabilities Index (ECI): Claude Opus 4.5 150.1 · Grok 4.3 149.2 · GPT-5.4 mini 148.8
  • Lowest priceGrok 4.3Grok 4.3 $1.56 · GPT-5.4 mini $1.69 · Claude Opus 4.5 $10.00 per 1M tokens (3:1 blend)
  • Longest contextGrok 4.3Grok 4.3 1,000,000 · GPT-5.4 mini 400,000 · Claude Opus 4.5 200,000 tokens
  • Widest inputsClaude Opus 4.5 and Grok 4.3GPT-5.4 mini: Text, Images · Claude Opus 4.5: Text, Images, PDFs · Grok 4.3: Text, Images, PDFs
  • Self-hostingNo open weightsAll three are available only through APIs
How the score is built
MeasureWeightGPT-5.4 miniClaude Opus 4.5Grok 4.3
CapabilityCapabilities Index (ECI)50%777877
Price25%39241
Inputs & features15%708080
Context window10%443260
Overall100%63/10055/10067/100
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 Claude Opus 4.5 vs Grok 4.3 specifications side by side
SpecificationGPT-5.4 miniOpenAIClaude Opus 4.5AnthropicGrok 4.3xAI
Capability
Capabilities Index (ECI)148.8150.1 (best)149.2
ECI rank#56 of 148#48 of 148 (best)#55 of 148
GPQA DiamondGraduate-level science questions86.9%86.1%88.8% (best)
FrontierMath Tiers 1–3Research-level mathematics51.2% (best)34.4%42.8%
OTIS Mock AIME 2024–2025Competition mathematics88.9%86.1%93.3% (best)
SWE-bench VerifiedFixing real GitHub issues—76.7%—
SimpleQA VerifiedShort factual questions29.4%45.7% (best)33.2%
Price per million tokens
Input$0.75 (best)$5.00$1.25
Output$4.50$25.00$2.50 (best)
Cached input$0.075 (best)$0.50$0.20
Blended (3:1)$1.69$10.00$1.56 (best)
Long-context rateSame rateSame rateOver 200K: $2.50 / $5.00
Price sourceOfficial OpenAI APIOfficial Anthropic APIOfficial xAI API
Limits
Context window400,000 tokens200,000 tokens1,000,000 tokens (best)
Max output128,000 tokens (best)64,000 tokens30,000 tokens
Inputs and features
TextYesYesYes
ImagesYesYesYes
PDFsNoYesYes
AudioNoNoNo
VideoNoNoNo
ReasoningYeslow · medium · high · xhighYeslow · medium · highYeslow · medium · high
Tool callingYesYesYes
Structured outputYesYesYes
Availability
WeightsProprietaryProprietaryProprietary
API model IDgpt-5.4-miniclaude-opus-4-5grok-4.3
API providers29 (best)2827
ReleasedMar 17, 2026Nov 24, 2025Apr 17, 2026
Knowledge cutoffAug 31, 2025May 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-5.4 mini$16.50
  • Claude Opus 4.5$100.00
  • Grok 4.3$17.50
04 — Questions

Which should you choose?

Which is better: GPT-5.4 mini, Claude Opus 4.5 or Grok 4.3?

Grok 4.3 is the better all-round choice, scoring 67/100 against GPT-5.4 mini (63) and Claude Opus 4.5 (55). It leads on context window. The score weighs capability 50%, price 25%, inputs & features 15%, context window 10%.

Which is cheaper, GPT-5.4 mini, Claude Opus 4.5 or Grok 4.3?

Grok 4.3 is cheaper at $1.25 input / $2.50 output per million tokens (official xAI API price). GPT-5.4 mini costs $0.75 input / $4.50 output per million tokens (official OpenAI API price); Claude Opus 4.5 costs $5.00 input / $25.00 output per million tokens (official Anthropic API price). At a typical mix of three input tokens to one output token, that is $1.56 per million tokens for Grok 4.3 versus $1.69 for GPT-5.4 mini (1.1× as much) and $10.00 for Claude Opus 4.5 (6.4× as much).

Which scores higher on benchmarks?

Claude Opus 4.5 scores higher on the Capabilities Index (ECI): Claude Opus 4.5 150.1 (#48 of 148), Grok 4.3 149.2 (#55 of 148) and GPT-5.4 mini 148.8 (#56 of 148). The confidence ranges of the top two overlap (147.9–153.0 vs 147.6–150.8), so treat the gap as small. On individual benchmarks: GPQA Diamond — Grok 4.3 88.8%, GPT-5.4 mini 86.9%, Claude Opus 4.5 86.1%; FrontierMath Tiers 1–3 — GPT-5.4 mini 51.2%, Grok 4.3 42.8%, Claude Opus 4.5 34.4%; OTIS Mock AIME 2024–2025 — Grok 4.3 93.3%, GPT-5.4 mini 88.9%, Claude Opus 4.5 86.1%; SimpleQA Verified — Claude Opus 4.5 45.7%, Grok 4.3 33.2%, GPT-5.4 mini 29.4%.

Which is better for coding?

There are no published SWE-bench Verified results for GPT-5.4 mini and Grok 4.3 yet, so there is no like-for-like coding score. On overall capability, Claude Opus 4.5 leads, which tends to carry over to coding, but test on your own codebase. All three support tool calling for agent workflows.

Which has the bigger context window?

Grok 4.3 has the largest context window at 1,000,000 tokens, against 400,000 for GPT-5.4 mini and 200,000 for Claude Opus 4.5. Maximum output per response: GPT-5.4 mini up to 128,000, Claude Opus 4.5 up to 64,000, Grok 4.3 up to 30,000 tokens.

Which can read images, PDFs, audio or video?

GPT-5.4 mini accepts text and images; Claude Opus 4.5 accepts text, images and PDFs; Grok 4.3 accepts text, images and PDFs. Claude Opus 4.5 handles the widest range of inputs.

Are any of these open source?

No. GPT-5.4 mini, Claude Opus 4.5 and Grok 4.3 are proprietary and only available through APIs and apps.

Which is newer?

Grok 4.3 is the newest, released Apr 17, 2026. GPT-5.4 mini came out Mar 17, 2026; Claude Opus 4.5 came out Nov 24, 2025. Knowledge cutoff: GPT-5.4 mini Aug 31, 2025, Claude Opus 4.5 May 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.