ZMIME
Comparison · 2 models · Updated Oct 4, 2026

Claude Sonnet 5 vs Kimi K3

Too close to call on our weighted score (Claude Sonnet 5 66, Kimi K3 65). The right pick depends on what you value most.

  1. Anthropic

    Claude Sonnet 5

    Released Jun 30, 2026

    66/100
    • ECI156.3
    • Price$2.00 / $10.00
    • Context1M
    Full specs Remove Claude Sonnet 5

  2. Moonshot AI

    Kimi K3

    Released Jul 16, 2026

    65/100
    • ECI157.6
    • Price$3.00 / $15.00
    • Context1.05M
    Full specs Remove Kimi K3

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01 — Verdict

Too close to call

It is close. Our weighted score puts them within 1 points (Claude Sonnet 5 66/100, Kimi K3 65/100), so choose by what matters most for your work: Kimi K3 for raw capability and Claude Sonnet 5 on price. The score weighs capability 50%, price 25%, inputs & features 15%, context window 10%.

  • CapabilityKimi K3Capabilities Index (ECI): Kimi K3 157.6 · Claude Sonnet 5 156.3
  • Lowest priceClaude Sonnet 5Claude Sonnet 5 $4.00 · Kimi K3 $6.00 per 1M tokens (3:1 blend)
  • Longest contextKimi K3Kimi K3 1,048,576 · Claude Sonnet 5 1,000,000 tokens
  • Widest inputsSame inputsClaude Sonnet 5: Text, Images, PDFs · Kimi K3: Text, Images, Video
  • Self-hostingKimi K3Publishes downloadable weights
How the score is built
MeasureWeightClaude Sonnet 5Kimi K3
CapabilityCapabilities Index (ECI)50%8688
Price25%2113
Inputs & features15%8080
Context window10%6061
Overall100%66/10065/100
02 — Side by side

Every spec in one table

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

Claude Sonnet 5 vs Kimi K3 specifications side by side
SpecificationClaude Sonnet 5AnthropicKimi K3Moonshot AI
Capability
Capabilities Index (ECI)156.3157.6 (best)
ECI rank#23 of 148#13 of 148 (best)
GPQA DiamondGraduate-level science questions90.5%93.1% (best)
FrontierMath Tiers 1–3Research-level mathematics65.6%72.2% (best)
OTIS Mock AIME 2024–2025Competition mathematics94.7%97.2% (best)
SimpleQA VerifiedShort factual questions33.7%50.6% (best)
Price per million tokens
Input$2.00 (best)$3.00
Output$10.00 (best)$15.00
Cached input$0.20 (best)$0.30
Blended (3:1)$4.00 (best)$6.00
Long-context rateSame rateSame rate
Price sourceOfficial Anthropic APIOfficial Moonshot AI API
Limits
Context window1,000,000 tokens1,048,576 tokens (best)
Max output128,000 tokens131,072 tokens (best)
Inputs and features
TextYesYes
ImagesYesYes
PDFsYesNo
AudioNoNo
VideoNoYes
ReasoningYeslow · medium · high · xhigh · maxYeslow · high · max
Tool callingYesYes
Structured outputYesYes
Availability
WeightsProprietaryOpen
API model IDclaude-sonnet-5kimi-k3
API providers3868 (best)
ReleasedJun 30, 2026Jul 16, 2026
Knowledge cutoffJan 31, 2026—
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 5$40.00
  • Kimi K3$60.00
04 — Questions

Which should you choose?

Which is better: Claude Sonnet 5 or Kimi K3?

It is close. Our weighted score puts them within 1 points (Claude Sonnet 5 66/100, Kimi K3 65/100), so choose by what matters most for your work: Kimi K3 for raw capability and Claude Sonnet 5 on price. The score weighs capability 50%, price 25%, inputs & features 15%, context window 10%.

Which is cheaper, Claude Sonnet 5 or Kimi K3?

Claude Sonnet 5 is cheaper at $2.00 input / $10.00 output per million tokens (official Anthropic 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 $4.00 per million tokens for Claude Sonnet 5 versus $6.00 for Kimi K3 (1.5× as much).

Which scores higher on benchmarks?

Kimi K3 scores higher on the Capabilities Index (ECI): Kimi K3 157.6 (#13 of 148) and Claude Sonnet 5 156.3 (#23 of 148). The confidence ranges of the top two overlap (154.9–160.4 vs 153.6–158.8), so treat the gap as small. On individual benchmarks: GPQA Diamond — Kimi K3 93.1%, Claude Sonnet 5 90.5%; FrontierMath Tiers 1–3 — Kimi K3 72.2%, Claude Sonnet 5 65.6%; OTIS Mock AIME 2024–2025 — Kimi K3 97.2%, Claude Sonnet 5 94.7%; SimpleQA Verified — Kimi K3 50.6%, Claude Sonnet 5 33.7%.

Which is better for coding?

There are no published SWE-bench Verified results for Claude Sonnet 5 and 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. Both support tool calling for agent workflows.

Which has the bigger context window?

Kimi K3 has the largest context window at 1,048,576 tokens, against 1,000,000 for Claude Sonnet 5. Maximum output per response: Claude Sonnet 5 up to 128,000, Kimi K3 up to 131,072 tokens.

Which can read images, PDFs, audio or video?

Claude Sonnet 5 accepts text, images and PDFs; Kimi K3 accepts text, images and video. They handle the same number of input types.

Are any of these open source?

Kimi K3 publishes its weights and can be self-hosted; Claude Sonnet 5 is proprietary.

Which is newer?

Kimi K3 is the newest, released Jul 16, 2026. Claude Sonnet 5 came out Jun 30, 2026. Knowledge cutoff: Claude Sonnet 5 Jan 31, 2026.

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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