Kimi K3 vs Claude Opus 5
Kimi K3 is the better pick: it passed more tasks on the AIGROW small-business benchmark and has the lower list price. Kimi K3 passed 19 of 20 tasks and costs $3 in and $15 out per million tokens; Claude Opus 5 passed 17 and costs $5 in and $25 out.
AIGROW credit covers Claude Opus 5.5, Claude Fable 5.2, Claude Fable 5.1, GPT-6 Astra, Claude Sonnet 5.5, GPT-6.1 Sol, GPT-6.1 Terra, Grok 4.7 and Gemini 4 Argon. Claude Opus 5.5 below list price
$25 a month brings $110 of API credit and cancels any time; $25 once buys $100. US dollars, standard rate, shortest context band. Cost per pass from the AIGROW small-business benchmark. Newer comparison: Kimi K3.1 Pro vs Claude Opus 5.5
- Kimi K3
- $18.44
- Tasks passed
- 19 of 20
- Claude Opus 5
- $16.89
- Tasks passed
- 17 of 20
AIGROW small-business benchmark, failed runs included.
Kimi K3 is marketed for long-horizon coding and knowledge work, the same ground as Opus. Claude Opus 5 costs $16.89 per 1,000 passing answers on the AIGROW small-business benchmark, Kimi K3 $18.44. 1,000 support replies cost $25.00 on Claude Opus 5 and $15.00 on Kimi K3, so Claude Opus 5 costs 67% more.
What each one costs
The API price per million tokens and the cheapest app plan with each model, from the makers’ own pages. Each name opens that model’s full price page.
- Kimi K3
- On the Moonshot AI API, Kimi K3 costs $3 per million input tokens and $15 per million output tokens.
- Claude Opus 5
- On the Anthropic API, Claude Opus 5 costs $5 per million input tokens and $25 per million output tokens.
Side by side
Each maker’s published rate for its standard tier. Cached input is what a repeated prompt prefix costs once the provider has stored it.
| Fact | Kimi K3 | Claude Opus 5 |
|---|---|---|
| Maker | Moonshot AI | Anthropic |
| Tier | Flagships | Flagships |
| Input, per M tokens | $3.00 | $5.00 |
| Output, per M tokens | $15.00 | $25.00 |
| Cached input | $0.30 | $0.50 |
| Context window | 1.05M | 1M |
| Released | Jul 2026 | 24 Jul 2026 |
| Weights | Open weights | Closed weights |
What a job costs on each
1,000 runs of each job at the two list prices. The gap moves from job to job because the models price input, output and cached context differently.
| Job | Kimi K3 | Claude Opus 5 | Cheaper |
|---|---|---|---|
| Support reply3,000 in, 400 out. | $15.00 | $25.00 | Kimi K3, 40% less |
| Document summary25,000 in, 1,000 out. | $90.00 | $150 | Kimi K3, 40% less |
| Agent task80,000 in (70,000 cached), 3,000 out. | $96.00 | $160 | Kimi K3, 40% less |
The token counts are ours, chosen to look like real work; the prices are the makers’. A model with no published cache price bills the agent task’s repeated context at its full input rate.
The small print
What each base rate leaves out, from the makers’ own pages: surcharges, discounts, promotions and cache pricing.
- Kimi K3
- Moonshot now calls it the previous-generation K3, next to Kimi K3.1 Pro. Cache write $3 (5 min TTL) or $6 (1 h TTL). Open weights on Hugging Face (moonshotai/Kimi-K3). Changelog gives the month only. Moonshot AI’s pricing page
- Claude Opus 5
- Legacy model, still available; Anthropic now points most work to Claude Opus 5.5 and lists no retirement before 24 July 2027. Cache write $6.25 (5 min) or $10 (1 h). Fast mode $10 / $50. Batch API 50% off. US-only inference bills 1.1x. Full context window billed at standard rates. Anthropic’s pricing page
Other comparisons
Every head to head on the list that involves Kimi K3 or Claude Opus 5.
Compare Kimi K3 and Claude Opus 5 with 52 other models
The price list sets every model’s input and output price side by side, with what a support reply, a document summary and an agent task cost on each.
Prices checked 12 November 2026