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Comparison · 3 models · Updated Oct 4, 2026

Grok 4.3 vs Kimi K2 Thinking vs GPT-5.4 mini

Grok 4.3 comes out ahead, 67 to 63 and 58 on our weighted score, though Kimi K2 Thinking is 31% cheaper per token.

  1. Our pick

    xAI

    Grok 4.3

    Released Apr 17, 2026

    67/100
    • ECI149.2
    • Price$1.25 / $2.50
    • Context1M
    Full specs Remove Grok 4.3

  2. Moonshot AI

    Kimi K2 Thinking

    Released Nov 6, 2025

    58/100
    • ECI146.0
    • Price$0.60 / $2.50
    • Context262K
    Full specs Remove Kimi K2 Thinking

  3. 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
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 Kimi K2 Thinking (58). It leads on inputs & features and context window. Kimi K2 Thinking wins on price. The score weighs capability 50%, price 25%, inputs & features 15%, context window 10%.

  • CapabilityGrok 4.3Capabilities Index (ECI): Grok 4.3 149.2 · GPT-5.4 mini 148.8 · Kimi K2 Thinking 146.0
  • Lowest priceKimi K2 ThinkingKimi K2 Thinking $1.07 · Grok 4.3 $1.56 · GPT-5.4 mini $1.69 per 1M tokens (3:1 blend)
  • Longest contextGrok 4.3Grok 4.3 1,000,000 · GPT-5.4 mini 400,000 · Kimi K2 Thinking 262,144 tokens
  • Widest inputsGrok 4.3Grok 4.3: Text, Images, PDFs · Kimi K2 Thinking: Text · GPT-5.4 mini: Text, Images
  • Self-hostingKimi K2 ThinkingPublishes downloadable weights
How the score is built
MeasureWeightGrok 4.3Kimi K2 ThinkingGPT-5.4 mini
CapabilityCapabilities Index (ECI)50%777377
Price25%414839
Inputs & features15%803570
Context window10%603744
Overall100%67/10058/10063/100
02 — Side by side

Every spec in one table

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

Grok 4.3 vs Kimi K2 Thinking vs GPT-5.4 mini specifications side by side
SpecificationGrok 4.3xAIKimi K2 ThinkingMoonshot AIGPT-5.4 miniOpenAI
Capability
Capabilities Index (ECI)149.2 (best)146.0148.8
ECI rank#55 of 148 (best)#72 of 148#56 of 148
GPQA DiamondGraduate-level science questions88.8% (best)84.2%86.9%
FrontierMath Tiers 1–3Research-level mathematics42.8%—51.2% (best)
OTIS Mock AIME 2024–2025Competition mathematics93.3% (best)83.1%88.9%
SimpleQA VerifiedShort factual questions33.2% (best)—29.4%
Price per million tokens
Input$1.25$0.60 (best)$0.75
Output$2.50 (best)$2.50 (best)$4.50
Cached input$0.20—$0.075 (best)
Blended (3:1)$1.56$1.07 (best)$1.69
Long-context rateOver 200K: $2.50 / $5.00Same rateSame rate
Price sourceOfficial xAI APIMedian of 10 providersOfficial OpenAI API
Limits
Context window1,000,000 tokens (best)262,144 tokens400,000 tokens
Max output30,000 tokens262,144 tokens (best)128,000 tokens
Inputs and features
TextYesYesYes
ImagesYesNoYes
PDFsYesNoNo
AudioNoNoNo
VideoNoNoNo
ReasoningYeslow · medium · highYesYeslow · medium · high · xhigh
Tool callingYesYesYes
Structured outputYesNoYes
Availability
WeightsProprietaryOpenProprietary
API model IDgrok-4.3—gpt-5.4-mini
API providers271029 (best)
ReleasedApr 17, 2026Nov 6, 2025Mar 17, 2026
Knowledge cutoff—Aug 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.

  • Grok 4.3$17.50
  • Kimi K2 Thinking$11.00
  • GPT-5.4 mini$16.50
04 — Questions

Which should you choose?

Which is better: Grok 4.3, Kimi K2 Thinking or GPT-5.4 mini?

Grok 4.3 is the better all-round choice, scoring 67/100 against GPT-5.4 mini (63) and Kimi K2 Thinking (58). It leads on inputs & features and context window. Kimi K2 Thinking wins on price. The score weighs capability 50%, price 25%, inputs & features 15%, context window 10%.

Which is cheaper, Grok 4.3, Kimi K2 Thinking or GPT-5.4 mini?

Kimi K2 Thinking is cheaper at $0.60 input / $2.50 output per million tokens (median across 10 API providers). Grok 4.3 costs $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). At a typical mix of three input tokens to one output token, that is $1.07 per million tokens for Kimi K2 Thinking versus $1.56 for Grok 4.3 (1.5× as much) and $1.69 for GPT-5.4 mini (1.6× as much).

Which scores higher on benchmarks?

Grok 4.3 scores higher on the Capabilities Index (ECI): Grok 4.3 149.2 (#55 of 148), GPT-5.4 mini 148.8 (#56 of 148) and Kimi K2 Thinking 146.0 (#72 of 148). The confidence ranges of the top two overlap (147.6–150.8 vs 147.1–150.5), so treat the gap as small. On individual benchmarks: GPQA Diamond — Grok 4.3 88.8%, GPT-5.4 mini 86.9%, Kimi K2 Thinking 84.2%; OTIS Mock AIME 2024–2025 — Grok 4.3 93.3%, GPT-5.4 mini 88.9%, Kimi K2 Thinking 83.1%.

Which is better for coding?

There are no published SWE-bench Verified results for Grok 4.3, Kimi K2 Thinking and GPT-5.4 mini yet, so there is no like-for-like coding score. On overall capability, Grok 4.3 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 262,144 for Kimi K2 Thinking. Maximum output per response: Grok 4.3 up to 30,000, Kimi K2 Thinking up to 262,144, GPT-5.4 mini up to 128,000 tokens.

Which can read images, PDFs, audio or video?

Grok 4.3 accepts text, images and PDFs; Kimi K2 Thinking accepts text; GPT-5.4 mini accepts text and images. Grok 4.3 handles the widest range of inputs.

Are any of these open source?

Kimi K2 Thinking publishes its weights and can be self-hosted; Grok 4.3 and GPT-5.4 mini is proprietary.

Which is newer?

Grok 4.3 is the newest, released Apr 17, 2026. GPT-5.4 mini came out Mar 17, 2026; Kimi K2 Thinking came out Nov 6, 2025. Knowledge cutoff: Kimi K2 Thinking Aug 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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