Neither wins outright: Anthropic: Claude Sonnet 4.5 is the pick when you need file / PDF input, MoonshotAI: Kimi K3 (batch) when cost matters at scale.
| Spec | Anthropic: Claude Sonnet 4.5 | MoonshotAI: Kimi K3 (batch) |
|---|---|---|
| Provider | Anthropic | Moonshotai |
| Input price (per 1M tokens) | $3.00 | $2.28 |
| Output price (per 1M tokens) | $15.00 | $11.40 |
| Blended price (3:1 input/output) | $6.00 | $4.56 |
| Cheaper than … of all models we track | 8% | 12% |
| Context window | 1M tokens (~1,500 pages) | 1.0M tokens (~1,573 pages) |
| Larger context than … of all models | 69% | 81% |
| Max output per response | 64K tokens (~48,000 words) | 16K tokens (~12,300 words) |
| Input types | text, image, file | text, image, video |
| Output types | text | text |
| Free variant | No | No |
| Listed since | 2025-09-29 | 2026-07-16 |
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 4.5 | MoonshotAI: Kimi K3 (batch) | Difference |
|---|---|---|---|
| Customer-support chatbot 50,000 conversations — each a 6-turn conversation (1,500 in / 400 out tokens) | $525 | $399 | MoonshotAI: Kimi K3 (batch) saves $126 |
| RAG search over documents 20,000 questions — each a question answered from ~8 retrieved passages (6,000 in / 500 out tokens) | $510 | $388 | MoonshotAI: Kimi K3 (batch) saves $122 |
| 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) | $540 | $410 | MoonshotAI: Kimi K3 (batch) saves $130 |
| Batch summarisation 10,000 documents — each a 6,000-word report summarised to a page (8,000 in / 600 out tokens) | $330 | $251 | MoonshotAI: Kimi K3 (batch) saves $79.20 |
| Long-document analysis 500 documents — each a 150-page contract or codebase read in one pass (100,000 in / 2,000 out tokens) | $165 | $125 | MoonshotAI: Kimi K3 (batch) saves $39.60 |
| Capability | Anthropic: Claude Sonnet 4.5 | MoonshotAI: Kimi K3 (batch) | What it lets you do |
|---|---|---|---|
| Tool / function calling | ✓ Yes | ✓ Yes | call your APIs and run agent loops |
| Structured output (JSON schema) | ✓ Yes | ✓ Yes | return JSON that validates against your schema |
| Reasoning / thinking mode | ✓ Yes | ✓ Yes | spend extra tokens thinking before answering hard problems |
| Image input | ✓ Yes | ✓ Yes | read 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) | — | ✓ Yes | repeat 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.
| Date | Model | Input / 1M | Output / 1M |
|---|---|---|---|
| 2026-09-23 | MoonshotAI: Kimi K3 (batch) | $2.28 | $11.40 |
Neither wins outright: Anthropic: Claude Sonnet 4.5 is the pick when you need file / PDF input, MoonshotAI: Kimi K3 (batch) when cost matters at scale. In short: Anthropic: Claude Sonnet 4.5 when you need file / PDF input, you need built-in web search, you generate long outputs in one go; MoonshotAI: Kimi K3 (batch) when cost matters at scale, you need seed (reproducible sampling), you want the newer model.
MoonshotAI: Kimi K3 (batch) is cheaper: $4.56 vs $6.00 per 1M tokens at a typical 3:1 input/output mix, 24% less. For 50,000 support conversations a month that is $399 against $525.
Anthropic: Claude Sonnet 4.5 costs $3.00 per 1M input tokens and $15.00 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.
MoonshotAI: Kimi K3 (batch): 1.0M tokens, about 1,573 pages, against 1M (about 1,500 pages) for Anthropic: Claude Sonnet 4.5.
Tool calling — Anthropic: Claude Sonnet 4.5: yes, MoonshotAI: Kimi K3 (batch): yes. JSON-schema structured output — Anthropic: Claude Sonnet 4.5: yes, MoonshotAI: Kimi K3 (batch): yes.
Yes, both accept image input.
No free variant is listed for either; both are pay-per-token.
Anthropic: Claude Sonnet 4.5 can write up to 64K tokens (about 48,000 words) per response; MoonshotAI: Kimi K3 (batch) up to 16K (about 12,300 words).
Anthropic: Claude Sonnet 4.5 was listed on 2025-09-29; MoonshotAI: Kimi K3 (batch) on 2026-07-16.
Anthropic: Claude Sonnet 4.5: price unchanged since we started tracking it on 2026-03-10. 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.
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