Kimi K3.1 Pro vs Claude Opus 5.5
There is no quality verdict yet: the AIGROW small-business benchmark has not run either model. On price, Kimi K3.1 Pro costs less: $2 in and $10 out per million tokens, against $4 in and $20 out for Claude Opus 5.5.
Run Claude Opus 5.5 up to 60% 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. Price only: the benchmark has not run both.
- Kimi K3.1 Pro
- $10.00
- Claude Opus 5.5
- $20.00
- Kimi K3.1 Pro, per M tokens
- $2 / $10
- Claude Opus 5.5, per M tokens
- $4 / $20
3,000 tokens in and 400 out each, at list price.
Moonshot's open-weight flagship against Anthropic's, aimed at long-horizon coding at half the Opus list price. 1,000 support replies cost $20.00 on Claude Opus 5.5 and $10.00 on Kimi K3.1 Pro, so Claude Opus 5.5 costs twice as much. Prices are the makers’ own, checked on 12 November 2026.
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 K3.1 Pro
- On the Moonshot AI API, Kimi K3.1 Pro costs $2 per million input tokens and $10 per million output tokens.
- Claude Opus 5.5
- On the Anthropic API, Claude Opus 5.5 costs $4 per million input tokens and $20 per million output tokens. In Claude, the cheapest plan with it is Pro at $20/mo. Plan prices read 22 October 2026. AIGROW API credit runs Claude Opus 5.5 at $1.60 / $8.00 per million input / output tokens, up to 60% below list price. See API credit
$25 a month brings $110 of API credit and cancels any time; $25 once buys $100.
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 K3.1 Pro | Claude Opus 5.5 |
|---|---|---|
| Maker | Moonshot AI | Anthropic |
| Tier | Flagships | Flagships |
| Input, per M tokens | $2.00 | $4.00 |
| Output, per M tokens | $10.00 | $20.00 |
| Cached input | $0.20 | $0.20 |
| Context window | 1.05M | 1M |
| Released | Not published | 22 Sep 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 K3.1 Pro | Claude Opus 5.5 | Cheaper |
|---|---|---|---|
| Support reply3,000 in, 400 out. | $10.00 | $20.00 | Kimi K3.1 Pro, 50% less |
| Document summary25,000 in, 1,000 out. | $60.00 | $120 | Kimi K3.1 Pro, 50% less |
| Agent task80,000 in (70,000 cached), 3,000 out. | $64.00 | $114 | Kimi K3.1 Pro, 44% 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 K3.1 Pro
- Cache write $2 (5 min TTL) or $4 (1 h TTL). A highspeed variant costs $4 / $20. Batch 40% off. Moonshot calls it open-weight. Release date not stated on the official pages. Moonshot AI’s pricing page
- Claude Opus 5.5
- Cache read is 0.05x input on this model ($0.20). Cache write $5 (5 min) or $8 (1 h). Fast mode $8 / $40. Batch API 50% off. US-only inference bills 1.1x. Full context window billed at standard rates. Max output 128K. Anthropic’s pricing page
Other comparisons
Every head to head on the list that involves Kimi K3.1 Pro or Claude Opus 5.5.
- Gemini 4 Argon vs Claude Opus 5.5
- Muse Wonder vs Claude Opus 5.5
- Claude Opus 5.5 vs GPT-6 Astra
- Claude Opus 5.5 vs Claude Opus 5
- Claude Sonnet 5.5 vs Claude Opus 5.5
- Claude Fable 5.1 vs Claude Opus 5.5
- Claude Opus 5.5 vs Gemini 3.1 Pro (preview)
- Claude Opus 5.5 vs GPT-6.1 Sol
Run Claude Opus 5.5 up to 60% below list price
AIGROW API credit covers Claude Opus 5.5 at published rates never above the list prices here, and $25 buys $100 of credit.
Prices checked 12 November 2026