ZMIME
Comparison · 2 models · Updated Nov 2, 2026

Claude Sonnet 5.5 vs Inkling Small

Claude Sonnet 5.5 comes out ahead, 72 to 68 on our weighted score, though Inkling Small is 5× cheaper per token.

  1. Our pick

    Anthropic

    Claude Sonnet 5.5

    Released Sep 28, 2026New

    72/100
    • ECI166.7
    • Price$2.00 / $10.00
    • Context1M
    Full specs Remove Claude Sonnet 5.5

  2. Thinking Machines

    Inkling Small

    Released Jul 30, 2026

    68/100
    • ECI150.5
    • Price$0.58 / $1.44
    • Context1.05M
    Full specs Remove Inkling Small

  3. Add a model

    Make it a three-way comparison.

01 — Verdict

Claude Sonnet 5.5 is our pick

Claude Sonnet 5.5 is the better all-round choice, scoring 72/100 against Inkling Small (68). It leads on capability and inputs & features. Inkling Small wins on price. The score weighs capability 50%, price 25%, inputs & features 15%, context window 10%.

  • CapabilityClaude Sonnet 5.5Capabilities Index (ECI): Claude Sonnet 5.5 166.7 · Inkling Small 150.5
  • Lowest priceInkling SmallInkling Small $0.795 · Claude Sonnet 5.5 $4.00 per 1M tokens (3:1 blend)
  • Longest contextInkling SmallInkling Small 1,048,576 · Claude Sonnet 5.5 1,000,000 tokens
  • Widest inputsSame inputsClaude Sonnet 5.5: Text, Images, PDFs · Inkling Small: Text, Images, Audio
  • Self-hostingInkling SmallPublishes downloadable weights (Apache-2.0)
How the score is built
MeasureWeightClaude Sonnet 5.5Inkling Small
CapabilityCapabilities Index (ECI)50%9777
Price25%2052
Inputs & features15%8070
Context window10%6061
Overall100%72/10068/100
02 — Side by side

Every spec in one table

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

Claude Sonnet 5.5 vs Inkling Small specifications side by side
SpecificationClaude Sonnet 5.5AnthropicInkling SmallThinking Machines
Capability
Capabilities Index (ECI)166.7 (best)150.5
ECI rank#5 of 165 (best)#58 of 165
GPQA DiamondGraduate-level science questions95.6% (best)88.5%
FrontierMath Tiers 1–3Research-level mathematics88.8% (best)46.3%
OTIS Mock AIME 2024–2025Competition mathematics100% (best)90.0%
SimpleQA VerifiedShort factual questions46.5% (best)19.1%
Price per million tokens
Input$2.00$0.58 (best)
Output$10.00$1.44 (best)
Cached input$0.10 (best)$0.116
Blended (3:1)$4.00$0.795 (best)
Long-context rateSame rateSame rate
Price sourceOfficial Anthropic APIOfficial Thinking Machines API
Limits
Context window1,000,000 tokens1,048,576 tokens (best)
Max output128,000 tokens1,048,576 tokens (best)
Inputs and features
TextYesYes
ImagesYesYes
PDFsYesNo
AudioNoYes
VideoNoNo
ReasoningYeslow · medium · high · xhigh · maxYeslow · medium · high · xhigh · max
Tool callingYesYes
Structured outputYesNo
Availability
WeightsProprietaryOpenApache-2.0
API model IDclaude-sonnet-5-5thinkingmachines/Inkling-Small
API providers34 (best)12
ReleasedSep 28, 2026Jul 30, 2026
Knowledge cutoffJun 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 5.5$40.00
  • Inkling Small$8.68
04 — Questions

Which should you choose?

Which is better: Claude Sonnet 5.5 or Inkling Small?

Claude Sonnet 5.5 is the better all-round choice, scoring 72/100 against Inkling Small (68). It leads on capability and inputs & features. Inkling Small wins on price. The score weighs capability 50%, price 25%, inputs & features 15%, context window 10%.

Which is cheaper, Claude Sonnet 5.5 or Inkling Small?

Inkling Small is cheaper at $0.58 input / $1.44 output per million tokens (official Thinking Machines API price). Claude Sonnet 5.5 costs $2.00 input / $10.00 output per million tokens (official Anthropic API price). At a typical mix of three input tokens to one output token, that is $0.795 per million tokens for Inkling Small versus $4.00 for Claude Sonnet 5.5 (5× as much).

Which scores higher on benchmarks?

Claude Sonnet 5.5 scores higher on the Capabilities Index (ECI): Claude Sonnet 5.5 166.7 (#5 of 165) and Inkling Small 150.5 (#58 of 165). Their confidence ranges do not overlap (163.6–171.3 vs 147.7–152.4), so the gap is a real one. On individual benchmarks: GPQA Diamond — Claude Sonnet 5.5 95.6%, Inkling Small 88.5%; FrontierMath Tiers 1–3 — Claude Sonnet 5.5 88.8%, Inkling Small 46.3%; OTIS Mock AIME 2024–2025 — Claude Sonnet 5.5 100%, Inkling Small 90.0%; SimpleQA Verified — Claude Sonnet 5.5 46.5%, Inkling Small 19.1%.

Which is better for coding?

There are no published SWE-bench Verified results for Claude Sonnet 5.5 and Inkling Small yet, so there is no like-for-like coding score. On overall capability, Claude Sonnet 5.5 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?

Inkling Small has the largest context window at 1,048,576 tokens, against 1,000,000 for Claude Sonnet 5.5. Maximum output per response: Claude Sonnet 5.5 up to 128,000, Inkling Small up to 1,048,576 tokens.

Which can read images, PDFs, audio or video?

Claude Sonnet 5.5 accepts text, images and PDFs; Inkling Small accepts text, images and audio. They handle the same number of input types.

Are any of these open source?

Inkling Small publishes its weights (Apache-2.0) and can be self-hosted; Claude Sonnet 5.5 is proprietary.

Which is newer?

Claude Sonnet 5.5 is the newest, released Sep 28, 2026. Inkling Small came out Jul 30, 2026. Knowledge cutoff: Claude Sonnet 5.5 Jun 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 Nov 2, 2026.

05 — Keep comparing

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