Which is cheaper, Claude Sonnet 4.5 or Kimi K3?

Kimi K3, at $6.20 per million tokens against $20.61 for Claude Sonnet 4.5, three parts input to one part output, read on 16 Sept 2026.

Where is each one cheapest?

Claude Sonnet 4.5: $20.61 at Poe. Kimi K3: $6.20 at NanoGPT.

Can I buy both from one provider?

Yes. 29 providers sell both: NanoGPT, Nous Portal, TrustedRouter, Poe, OpenRouter, Merge Gateway, and more. The cheapest of them for the two together is NanoGPT.

Which holds more context?

Kimi K3, at 1M tokens against 1M.

Claude Sonnet 4.5 vs Kimi K3.

model vs model · prices as of 16 Sept 2026

Kimi K3 takes 2 of 5 rounds against Claude Sonnet 4.5. It is also the cheaper of the two to run, at $6.20 per million tokens against $20.61.

Anthropic

Claude Sonnet 4.5

$20.61/M tokens

cheapest we can explain, at Poe · $2.32 per 1,000 pages

1M context · tool calling · reads images

Poe ↗

Moonshot AIwins 2 rounds

Kimi K3

$6.20/M tokens

cheapest we can explain, at NanoGPT · $1.21 per 1,000 pages

1M context · tool calling · reads images · open weights

NanoGPT ↗

List price in (lower wins)

$3/M

List price out (lower wins)

$15/M

Cheapest we can explain (lower wins)

$20.61/M at Poe

$6.20/M at NanoGPT

Standard price (lower wins)

$24/M

Cost per 1,000 pages (lower wins)

$2.32

$1.21

Context

1M tokens

Open weights

yes

Tool calling

yes

Structured output

yes

Reads images

yes

Reasoning

yes

Released

29 Sept 2025

16 Jul 2026

Providers selling it

Price we measure against

the maker's own

Trains on your prompts (no is better)

not stated

Providers selling both · 29

NanoGPT$24 / $6.20
Nous Portal$24 / $17.25
TrustedRouter$25.32 / $16.46
Poe$20.61 / $24.24
OpenRouter$24 / $21.23
Merge Gateway$24 / $22.70
Jiekou$22.80 / $24
302.AI$24 / $24

Claude Sonnet 4.5 then Kimi K3, per million tokens · showing the 8 cheapest of 29

Go further

open in the compare tool →every price for Claude Sonnet 4.5 every price for Kimi K3

Add a third or fourth model, or switch the weighting, in the tool.

What moved in the last seven days

Claude Sonnet 4.5Nous Portal$2.40 / $12 $3 / $1525% dearer · 16 Sept 2026
Kimi K3Inference.net$3.95 / $19.80 $2.10 / $10.9545% cheaper · 16 Sept 2026
Kimi K3io.net Intelligence$3.10 / $15.50 $3.15 / $15.762% dearer · 16 Sept 2026
Kimi K3Morph$2.43 / $13.58 $2.25 / $12.607% cheaper · 16 Sept 2026
Kimi K3Nous Portal$1.87 / $9.36 $2.10 / $10.9515% dearer · 16 Sept 2026
Kimi K3OpenRouter$2.34 / $11.70 $2.65 / $13.2813% dearer · 16 Sept 2026
Kimi K3Sail Research$2.34 / $11.70 $2.65 / $13.2813% dearer · 16 Sept 2026
Claude Sonnet 4.5Requesty$3.30 / $16.50 $3 / $159% cheaper · 11 Sept 2026

Frequently asked

Which is cheaper, Claude Sonnet 4.5 or Kimi K3?: Kimi K3, at $6.20 per million tokens against $20.61 for Claude Sonnet 4.5, three parts input to one part output, read on 16 Sept 2026.
Where is each one cheapest?: Claude Sonnet 4.5: $20.61 at Poe. Kimi K3: $6.20 at NanoGPT.
Can I buy both from one provider?: Yes. 29 providers sell both: NanoGPT, Nous Portal, TrustedRouter, Poe, OpenRouter, Merge Gateway, and more. The cheapest of them for the two together is NanoGPT.
Which holds more context?: Kimi K3, at 1M tokens against 1M.

Prices exclude tax and are per million tokens, read 16 Sept 2026 from each provider's own catalog. The standard price blends three parts input to one part output; a page is 600 tokens in and 60 out. Bars are scaled to the larger value in each row.