ModelsAtlas
Explore

Anthropic: Claude Sonnet 5.5 (batch) vs MoonshotAI: Kimi K3 (batch)

Neither wins outright: Anthropic: Claude Sonnet 5.5 (batch) is the pick when cost matters at scale, MoonshotAI: Kimi K3 (batch) when you need seed (reproducible sampling).

Key numbers

SpecAnthropic: Claude Sonnet 5.5 (batch)MoonshotAI: Kimi K3 (batch)
ProviderAnthropicMoonshotai
Input price (per 1M tokens)$1.00$2.28
Output price (per 1M tokens)$5.00$11.40
Blended price (3:1 input/output)$2.00$4.56
Cheaper than … of all models we track25%12%
Context window1M tokens (~1,500 pages)1.0M tokens (~1,573 pages)
Larger context than … of all models69%81%
Max output per response128K tokens (~96,000 words)16K tokens (~12,300 words)
Input typestext, image, filetext, image, video
Output typestexttext
Free variantNoNo
Listed since2026-09-282026-07-16
Advertisement

What it costs for real workloads

Monthly cost at list price for five common workloads. Token counts per unit are stated so you can scale them to your own traffic. A workload that does not fit a model's context window is marked rather than priced.

Workload (per month)Anthropic: Claude Sonnet 5.5 (batch)MoonshotAI: Kimi K3 (batch)Difference
Customer-support chatbot
50,000 conversations — each a 6-turn conversation (1,500 in / 400 out tokens)
$175$399Anthropic: Claude Sonnet 5.5 (batch) saves $224
RAG search over documents
20,000 questions — each a question answered from ~8 retrieved passages (6,000 in / 500 out tokens)
$170$388Anthropic: Claude Sonnet 5.5 (batch) saves $218
Coding / tool-using agent
2,000 tasks — each a multi-step task with tool calls and file context (60,000 in / 6,000 out tokens)
$180$410Anthropic: Claude Sonnet 5.5 (batch) saves $230
Batch summarisation
10,000 documents — each a 6,000-word report summarised to a page (8,000 in / 600 out tokens)
$110$251Anthropic: Claude Sonnet 5.5 (batch) saves $141
Long-document analysis
500 documents — each a 150-page contract or codebase read in one pass (100,000 in / 2,000 out tokens)
$55.00$125Anthropic: Claude Sonnet 5.5 (batch) saves $70.40

Capabilities side by side

CapabilityAnthropic: Claude Sonnet 5.5 (batch)MoonshotAI: Kimi K3 (batch)What it lets you do
Tool / function calling✓ Yes✓ Yescall your APIs and run agent loops
Structured output (JSON schema)✓ Yes✓ Yesreturn JSON that validates against your schema
Reasoning / thinking mode✓ Yes✓ Yesspend extra tokens thinking before answering hard problems
Image input✓ Yes✓ Yesread screenshots, charts and scanned pages
Audio input——take speech or audio directly
File / PDF input✓ Yes—accept documents without your own parsing step
Image output——generate images, not just text
Built-in web search✓ Yes—answer from live web results
Seed (reproducible sampling)—✓ Yesrepeat a generation for tests and evals
Log-probabilities——read token confidence for classification and scoring

From each model's published parameters and input/output types. “—” means not advertised, not proven absent.

Price history

DateModelInput / 1MOutput / 1M
2026-09-23MoonshotAI: Kimi K3 (batch)$2.28$11.40

Which should you choose?

Choose Anthropic: Claude Sonnet 5.5 (batch) if…

  • cost matters at scale — it is 56% cheaper on a typical 3:1 input/output mix ($175 vs $399 a month for 50,000 support chats)
  • you need file / PDF input — to accept documents without your own parsing step; MoonshotAI: Kimi K3 (batch) does not advertise it
  • you need built-in web search — to answer from live web results; MoonshotAI: Kimi K3 (batch) does not advertise it
  • you generate long outputs in one go — up to 128K tokens (about 96,000 words) per response

Choose MoonshotAI: Kimi K3 (batch) if…

  • you need seed (reproducible sampling) — to repeat a generation for tests and evals; Anthropic: Claude Sonnet 5.5 (batch) does not advertise it

Frequently asked questions

Is Anthropic: Claude Sonnet 5.5 (batch) better than MoonshotAI: Kimi K3 (batch)?

Neither wins outright: Anthropic: Claude Sonnet 5.5 (batch) is the pick when cost matters at scale, MoonshotAI: Kimi K3 (batch) when you need seed (reproducible sampling). In short: Anthropic: Claude Sonnet 5.5 (batch) when cost matters at scale, you need file / PDF input, you need built-in web search, you generate long outputs in one go; MoonshotAI: Kimi K3 (batch) when you need seed (reproducible sampling).

Which is cheaper, Anthropic: Claude Sonnet 5.5 (batch) or MoonshotAI: Kimi K3 (batch)?

Anthropic: Claude Sonnet 5.5 (batch) is cheaper: $2.00 vs $4.56 per 1M tokens at a typical 3:1 input/output mix, 56% less. For 50,000 support conversations a month that is $175 against $399.

How much do Anthropic: Claude Sonnet 5.5 (batch) and MoonshotAI: Kimi K3 (batch) cost per million tokens?

Anthropic: Claude Sonnet 5.5 (batch) costs $1.00 per 1M input tokens and $5.00 per 1M output tokens; MoonshotAI: Kimi K3 (batch) costs $2.28 input and $11.40 output. Output tokens are billed separately, so long answers shift the gap.

Which has the bigger context window, Anthropic: Claude Sonnet 5.5 (batch) or MoonshotAI: Kimi K3 (batch)?

MoonshotAI: Kimi K3 (batch): 1.0M tokens, about 1,573 pages, against 1M (about 1,500 pages) for Anthropic: Claude Sonnet 5.5 (batch).

Do Anthropic: Claude Sonnet 5.5 (batch) and MoonshotAI: Kimi K3 (batch) support function calling and JSON output?

Tool calling — Anthropic: Claude Sonnet 5.5 (batch): yes, MoonshotAI: Kimi K3 (batch): yes. JSON-schema structured output — Anthropic: Claude Sonnet 5.5 (batch): yes, MoonshotAI: Kimi K3 (batch): yes.

Can Anthropic: Claude Sonnet 5.5 (batch) or MoonshotAI: Kimi K3 (batch) read images?

Yes, both accept image input.

Is Anthropic: Claude Sonnet 5.5 (batch) or MoonshotAI: Kimi K3 (batch) free to use?

No free variant is listed for either; both are pay-per-token.

What is the maximum output length of Anthropic: Claude Sonnet 5.5 (batch) and MoonshotAI: Kimi K3 (batch)?

Anthropic: Claude Sonnet 5.5 (batch) can write up to 128K tokens (about 96,000 words) per response; MoonshotAI: Kimi K3 (batch) up to 16K (about 12,300 words).

When were Anthropic: Claude Sonnet 5.5 (batch) and MoonshotAI: Kimi K3 (batch) released?

Anthropic: Claude Sonnet 5.5 (batch) was listed on 2026-09-28; MoonshotAI: Kimi K3 (batch) on 2026-07-16.

Has the price of Anthropic: Claude Sonnet 5.5 (batch) or MoonshotAI: Kimi K3 (batch) changed?

Anthropic: Claude Sonnet 5.5 (batch): price unchanged since we started tracking it on 2026-09-29. MoonshotAI: Kimi K3 (batch): input price cut 24% ($3.00 → $2.28/1M), output price cut 24% ($15.00 → $11.40/1M) on 2026-09-23.

About the two models

Compare Anthropic: Claude Sonnet 5.5 (batch) with other models

vs AI21: Jamba Large 1.7vs AionLabs: Aion 3.5vs AionLabs: Aion 3.5 Minivs AionLabs: Aion-1.0

Compare MoonshotAI: Kimi K3 (batch) with other models

vs AI21: Jamba Large 1.7vs AionLabs: Aion 3.5vs AionLabs: Aion 3.5 Minivs AionLabs: Aion-1.0
Advertisement