Kimi K3 vs Claude Opus 5.5
Kimi K3 costs $3.00 / $15.00 and Claude Opus 5.5 costs $4.00 / $20.00 per million input / output tokens. At a typical 3:1 mix, Kimi K3 is 1.3× cheaper than Claude Opus 5.5. But Claude Opus 5.5 scores clearly higher on Epoch AI’s Capabilities Index (169 vs 159, beyond the margin of error).
Price
Kimi K3 is 1.3× cheaper per token
On a coding agent: $779 vs $853 a month (9% less)
Capability
Claude Opus 5.5 scores higher
Kimi K3 159 (157–161)
Claude Opus 5.5 169 (166–172)
Claude Opus 5.5 169 (166–172)
Best value at Claude Opus 5.5’s level
GPT-6.1 Terra, 4× less
Level with or above Claude Opus 5.5 · $213 a month on a coding agent · Every option
Input
$3.00
per 1M
Output
$15.00
per 1M
Cached
$0.30
1M context
Input
$4.00
per 1M
Output
$20.00
per 1M
Cached
$0.20
1M context
Side by side
✓ marks the cheaper price, larger context window, bigger discount or higher score.
| Detail | Kimi K3 | Claude Opus 5.5 |
|---|---|---|
| Price per 1M tokens | ||
| Input | $3.00Lowest | $4.00 |
| Output | $15.00Lowest | $20.00 |
| Blended (3 in : 1 out) | $6.00Lowest | $8.00 |
| Cached input | $0.30 | $0.20Lowest |
| Batch or off-peak discount | 40% (batch) | 50% (batch)Largest |
| Long prompts | Same rate at any length | Same rate at any length |
| Limits and model | ||
| Context window | 1M | 1M |
| Capability score Epoch AI index | 159 | 169Highest |
| Arena text score 25 Sep 2026 | 1488 | 1509Highest |
| Released | 16 Jul 2026 | 22 Sep 2026 |
| Open weights | Yes | No |
| Status | Current | Current |
| Checked | ||
| Price checked | 2 Nov 2026 Kimi API pricing | 11 Nov 2026 Anthropic pricing |
Monthly cost on three workloads
List prices, no batch discount. The cached share applies where a model has a cache rate.
| Workload | Kimi K3 | Claude Opus 5.5 | Difference |
|---|---|---|---|
| Customer chat assistant50,000 conversations a month, about 2,000 tokens in and 400 out each; 50% cachedPrice this workload in the calculator | $465Lower | $610 | $145 |
| Document Q&A (RAG)20,000 questions a month over retrieved documents, 12,000 in and 600 out; 30% cachedPrice this workload in the calculator | $706Lower | $926 | $221 |
| Coding agent400 tasks a month, 40 steps each with a growing context; 85% cachedPrice this workload in the calculator | $649Lower | $738 | $88.75 |
How they differ
- Kimi K3 is cheaper on input ($3 vs $4).
- Kimi K3 is cheaper on output ($15 vs $20), which matters most for long answers and reasoning models.
- Kimi K3 accepts longer prompts (1M vs 1M tokens).
- Cached input is cheaper on Claude Opus 5.5 ($0.20 vs $0.30), which favours agents and chat apps that resend the same context.
- Kimi K3 has open weights, so you can also run it yourself or choose between hosts.
- On Epoch AI’s Capabilities Index, Claude Opus 5.5 scores clearly higher (169 vs 159), beyond the margin of error.
- On the Arena text leaderboard (25 Sep 2026), Claude Opus 5.5 scores higher (1509 vs 1488). Test both on your own prompts before deciding.
Recent changes
All changes- Moonshot launched Kimi K3.1 Pro at $2 / $10 per 1M tokens, with cached input at $0.20, a third below Kimi K3's $3 / $15.
- ▼ 20%Claude Opus 5.5 launched at $4 / $20 per 1M tokens, 20% below Opus 5.
$5 / $25→ $4 / $20 - Anthropic retired Claude Opus 4.1.
- Anthropic launched Claude Opus 5 at $5 / $25.
- Moonshot launched Kimi K3 at $3 / $15.
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