ZMIME
Comparison · 3 models · Updated Oct 4, 2026

GPT-5.4 vs Gemini 3.1 Pro Preview vs Kimi K3

Too close to call on our weighted score (Gemini 3.1 Pro Preview 68, Kimi K3 65, GPT-5.4 65). The right pick depends on what you value most.

  1. OpenAI

    GPT-5.4

    Released Mar 5, 2026

    65/100
    • ECI156.9
    • Price$2.50 / $15.00
    • Context1.05M
  2. Google

    Gemini 3.1 Pro Preview

    Released Feb 19, 2026

    68/100
    • ECI154.8
    • Price$2.00 / $12.00
    • Context1.05M
  3. Moonshot AI

    Kimi K3

    Released Jul 16, 2026

    65/100
    • ECI157.6
    • Price$3.00 / $15.00
    • Context1.05M
01 — Verdict

Too close to call

It is close. Our weighted score puts them within 3 points (Gemini 3.1 Pro Preview 68/100, Kimi K3 65/100, GPT-5.4 65/100), so choose by what matters most for your work: Kimi K3 for raw capability and Gemini 3.1 Pro Preview on price. The score weighs capability 50%, price 25%, inputs & features 15%, context window 10%.

  • CapabilityKimi K3Capabilities Index (ECI): Kimi K3 157.6 · GPT-5.4 156.9 · Gemini 3.1 Pro Preview 154.8
  • Lowest priceGemini 3.1 Pro PreviewGemini 3.1 Pro Preview $4.50 · GPT-5.4 $5.63 · Kimi K3 $6.00 per 1M tokens (3:1 blend)
  • Longest contextAbout the sameGPT-5.4 1,050,000 · Gemini 3.1 Pro Preview 1,048,576 · Kimi K3 1,048,576 tokens
  • Widest inputsGemini 3.1 Pro PreviewGPT-5.4: Text, Images, PDFs · Gemini 3.1 Pro Preview: Text, Images, PDFs, Audio, Video · Kimi K3: Text, Images, Video
  • Self-hostingKimi K3Publishes downloadable weights
How the score is built
MeasureWeightGPT-5.4Gemini 3.1 Pro PreviewKimi K3
CapabilityCapabilities Index (ECI)50%878488
Price25%141913
Inputs & features15%8010080
Context window10%616161
Overall100%65/10068/10065/100
02 — Side by side

Every spec in one table

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

GPT-5.4 vs Gemini 3.1 Pro Preview vs Kimi K3 specifications side by side
SpecificationGPT-5.4OpenAIGemini 3.1 Pro PreviewGoogleKimi K3Moonshot AI
Capability
Capabilities Index (ECI)156.9154.8157.6 (best)
ECI rank#16 of 148#31 of 148#13 of 148 (best)
GPQA DiamondGraduate-level science questions93.3%94.4% (best)93.1%
FrontierMath Tiers 1–3Research-level mathematics78.6% (best)59.7%72.2%
OTIS Mock AIME 2024–2025Competition mathematics97.8% (best)95.6%97.2%
SWE-bench VerifiedFixing real GitHub issues76.9% (best)75.6%—
SimpleQA VerifiedShort factual questions45.1%73.5% (best)50.6%
Price per million tokens
Input$2.50$2.00 (best)$3.00
Output$15.00$12.00 (best)$15.00
Cached input$0.25$0.20 (best)$0.30
Blended (3:1)$5.63$4.50 (best)$6.00
Long-context rateOver 272K: $5.00 / $22.50Over 200K: $4.00 / $18.00Same rate
Price sourceOfficial OpenAI APIOfficial Google APIOfficial Moonshot AI API
Limits
Context window1,050,000 tokens (best)1,048,576 tokens1,048,576 tokens
Max output128,000 tokens65,536 tokens131,072 tokens (best)
Inputs and features
TextYesYesYes
ImagesYesYesYes
PDFsYesYesNo
AudioNoYesNo
VideoNoYesYes
ReasoningYeslow · medium · high · xhighYeslow · medium · highYeslow · high · max
Tool callingYesYesYes
Structured outputYesYesYes
Availability
WeightsProprietaryProprietaryOpen
API model IDgpt-5.4gemini-3.1-pro-previewkimi-k3
API providers362668 (best)
ReleasedMar 5, 2026Feb 19, 2026Jul 16, 2026
Knowledge cutoffAug 31, 2025Jan 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$55.00
  • Gemini 3.1 Pro Preview$44.00
  • Kimi K3$60.00
04 — Questions

Which should you choose?

Which is better: GPT-5.4, Gemini 3.1 Pro Preview or Kimi K3?

It is close. Our weighted score puts them within 3 points (Gemini 3.1 Pro Preview 68/100, Kimi K3 65/100, GPT-5.4 65/100), so choose by what matters most for your work: Kimi K3 for raw capability and Gemini 3.1 Pro Preview on price. The score weighs capability 50%, price 25%, inputs & features 15%, context window 10%.

Which is cheaper, GPT-5.4, Gemini 3.1 Pro Preview or Kimi K3?

Gemini 3.1 Pro Preview is cheaper at $2.00 input / $12.00 output per million tokens (official Google API price). GPT-5.4 costs $2.50 input / $15.00 output per million tokens (official OpenAI API price); Kimi K3 costs $3.00 input / $15.00 output per million tokens (official Moonshot AI API price). At a typical mix of three input tokens to one output token, that is $4.50 per million tokens for Gemini 3.1 Pro Preview versus $5.63 for GPT-5.4 (1.3× as much) and $6.00 for Kimi K3 (1.3× as much).

Which scores higher on benchmarks?

Kimi K3 scores higher on the Capabilities Index (ECI): Kimi K3 157.6 (#13 of 148), GPT-5.4 156.9 (#16 of 148) and Gemini 3.1 Pro Preview 154.8 (#31 of 148). The confidence ranges of the top two overlap (154.9–160.4 vs 154.9–159.1), so treat the gap as small. On individual benchmarks: GPQA Diamond — Gemini 3.1 Pro Preview 94.4%, GPT-5.4 93.3%, Kimi K3 93.1%; FrontierMath Tiers 1–3 — GPT-5.4 78.6%, Kimi K3 72.2%, Gemini 3.1 Pro Preview 59.7%; OTIS Mock AIME 2024–2025 — GPT-5.4 97.8%, Kimi K3 97.2%, Gemini 3.1 Pro Preview 95.6%; SimpleQA Verified — Gemini 3.1 Pro Preview 73.5%, Kimi K3 50.6%, GPT-5.4 45.1%.

Which is better for coding?

There are no published SWE-bench Verified results for Kimi K3 yet, so there is no like-for-like coding score. On overall capability, Kimi K3 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?

Their context windows are effectively the same size: GPT-5.4 1,050,000, Gemini 3.1 Pro Preview 1,048,576 and Kimi K3 1,048,576 tokens. Maximum output per response: GPT-5.4 up to 128,000, Gemini 3.1 Pro Preview up to 65,536, Kimi K3 up to 131,072 tokens.

Which can read images, PDFs, audio or video?

GPT-5.4 accepts text, images and PDFs; Gemini 3.1 Pro Preview accepts text, images, PDFs, audio and video; Kimi K3 accepts text, images and video. Gemini 3.1 Pro Preview handles the widest range of inputs.

Are any of these open source?

Kimi K3 publishes its weights and can be self-hosted; GPT-5.4 and Gemini 3.1 Pro Preview is proprietary.

Which is newer?

Kimi K3 is the newest, released Jul 16, 2026. GPT-5.4 came out Mar 5, 2026; Gemini 3.1 Pro Preview came out Feb 19, 2026. Knowledge cutoff: GPT-5.4 Aug 31, 2025, Gemini 3.1 Pro Preview Jan 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.