text model comparison
Claude Opus 5 vs Kimi K3
Claude Opus 5 and Kimi K3 are both current text models, from Anthropic and Moonshot Kimi. Kimi K3 is 40% cheaper per 1M input tokens than Claude Opus 5, $3 vs $5. On Arena Text, Claude Opus 5 scores 1490 Elo and Kimi K3 1488 Elo (Arena, measured October 8, 2026). Both accept about 1.05M tokens of context (1,048,576 and 1,000,000).
Data verified October 12, 2026 · Dataset 2026-10-12
Side by side
Standard-tier prices in effect today. The better value in each row is highlighted.
| Fact | Claude Opus 5 | Kimi K3 |
|---|---|---|
| Price per 1M input tokens | $5 | $3 (better) |
| Price per 1M output tokens | $25 | $15 (better) |
| Cost of 10M input and 2M output tokens | $100 | $60 (better) |
| Arena Text | 1490 Elo (#6 of 39) (better) | 1488 Elo (#7 of 39) |
| GPQA Diamond | 93.9% (#10 of 37) (better) | 93.1% (#15 of 37) |
| FrontierMath Tiers 1-3 (v2) | 85.6% (#10 of 37) (better) | 72.2% (#19 of 37) |
| SimpleQA Verified | 59.9% (#15 of 34) (better) | 50.6% (#18 of 34) |
| Provider | Anthropic | Moonshot Kimi |
| Release date | July 24, 2026 | July 16, 2026 |
| Access | API only | API and open weights |
| Context window | 1,000,000 tokens | 1,048,576 tokens |
| Max output | 128,000 tokens | Not reported |
| Input | text, image | text, image |
| Output | text | text |
When to choose each
Claude Opus 5
Best for
- Complex agentic coding and enterprise work as the general-purpose default before reaching for Fable 5.1
- Latency-sensitive work that can justify Fast mode pricing
Watch out for
- Fast mode pricing applies to the whole request, including above 200K input tokens, so it doubles the effective rate rather than adding a surcharge
- Cache reads are $0.50 per million (the standard 0.1x), five times Fable 5.1’s $0.25, even though Opus 5 is the cheaper model on base tokens. A cache-heavy agent loop can invert the expected cost ordering between the two.
Kimi K3
Best for
- Teams that want a frontier-scale model they can also self-host, with one architecture across both paths
- Long-context work at mid-tier hosted pricing
Watch out for
- Hosted rates match Claude Sonnet 5 exactly at $3 / $15 while offering a larger context window, so the comparison turns on capability rather than price
- Running the open weights shifts cost to infrastructure, which the token rates recorded here do not represent
- Moonshot’s self-reported results place it ahead of Claude Opus 4.8 and GPT-5.5 but behind Claude Fable 5 and GPT-5.6 Sol; none of this was reproduced independently here
Claude Opus 5 vs Kimi K3 FAQ
Which is cheaper, Claude Opus 5 or Kimi K3?
Kimi K3 is 40% cheaper per 1M input tokens than Claude Opus 5, $3 vs $5. For 10M input and 2M output tokens, Claude Opus 5 costs $100 and Kimi K3 $60 at standard rates.
Which scores higher on independent benchmarks, Claude Opus 5 or Kimi K3?
Claude Opus 5 leads on Arena Text, 1490 Elo to 1488 Elo; Claude Opus 5 leads on GPQA Diamond, 93.9% to 93.1%; Claude Opus 5 leads on FrontierMath Tiers 1-3 (v2), 85.6% to 72.2%. Scores are independent evaluations, not either vendor's launch figures.
Which has the larger context window, Claude Opus 5 or Kimi K3?
Both accept about 1.05M tokens of context (1,048,576 and 1,000,000).
Can I run Claude Opus 5 or Kimi K3 myself?
Kimi K3 is released as open weights you can run yourself; Claude Opus 5 is available through its provider's API only.
Related comparisons
Production evaluation
Choosing between Claude Opus 5 and Kimi K3?
Public benchmarks narrow the shortlist. We run both on your own tasks, data and cost limits, then build the routing and review controls to run the winner in production.
- A head-to-head evaluation on your real workload
- Routing between models by cost and difficulty