High-volume, cost-sensitive work
Choose o3
o3 costs 13% less on a typical mix of three input tokens for every output token ($3.50 against $4.00 per million tokens).
Kimi K3.1 Pro vs o3: price, context and capabilities
Choose Kimi K3.1 Pro for reused prompts and documents (RAG, agents), very long inputs and the latest release. Choose o3 for high-volume, cost-sensitive work and writing and code generation.
In short
- o3 is 13% cheaper than Kimi K3.1 Pro at the headline price ($3.50 / 1M tokens vs $4.00 / 1M tokens).
- Kimi K3.1 Pro reads more per request: 1.05M tokens against 200k.
- Kimi K3.1 Pro is the newer model (Oct 23, 2026, against Apr 16, 2025).
- Only o3 offers batch api.
Which should you choose?
Each answer below comes straight from the published prices, specifications and independent benchmark results.
Writing and code generation
Choose o3
o3 charges $8.00 per million output tokens, against $10.00 for Kimi K3.1 Pro. Output dominates the bill when answers are long.
Reused prompts and documents (RAG, agents)
Choose Kimi K3.1 Pro
Kimi K3.1 Pro charges $0.20 per million cached input tokens, against $0.50 for o3.
Very long inputs
Choose Kimi K3.1 Pro
Kimi K3.1 Pro reads up to 1.05M tokens per request, against 200k for o3.
Latest release
Choose Kimi K3.1 Pro
Kimi K3.1 Pro is the newer release (Oct 23, 2026, against Apr 16, 2025 for o3).
Monthly cost at three volumes
| Volume | Kimi K3.1 Pro | o3 | Difference |
|---|---|---|---|
| Prototype: 1M input, 250K output tokens | $4.50 | $4.00 | o3, $0.50 less |
| Production: 20M input, 5M output tokens | $90.00 | $80.00 | o3, $10.00 less |
| Scale: 500M input, 100M output tokens | $2,000 | $1,800 | o3, $200.00 less |
Standard rates, without caching or batch discounts. Volumes are per month.
Specifications side by side
| Kimi K3.1 Pro | o3 | |
|---|---|---|
| Provider | Moonshot AI | OpenAI |
| Category | Language models | Language models |
| Status | Generally available | Legacy |
| Headline price | $4.00 / 1M tokens | $3.50 / 1M tokens |
| Input | $2.00 / 1M tokens | $2.00 / 1M tokens |
| Output | $10.00 / 1M tokens | $8.00 / 1M tokens |
| Cached input | $0.20 / 1M tokens | $0.50 / 1M tokens |
| Context window | 1.05M | 200k |
| Max output | 944k | 100k |
| Released | Oct 23, 2026 | Apr 16, 2025 |
| Knowledge cutoff | No data | June 2024 |
| Licence | Proprietary | Proprietary |
| Capabilities | Vision, Reasoning, Tool calling, Structured output, Prompt caching | Vision, Reasoning, Tool calling, Structured output, Prompt caching, Batch API |
| API model id | kimi-k3.1-pro | o3 |
Benchmarks side by side
Leader in bold.
| Benchmark | Kimi K3.1 Pro | o3 |
|---|---|---|
| Terminal-Bench Hard | No data | 37.1% |
| GPQA Diamond | No data | 82.7% |
| Humanity's Last Exam | No data | 20.1% |
| IFBench (instruction following) | No data | 71.4% |
| τ²-Bench (agentic tool use) | No data | 80.7% |
| MMMU-Pro (visual reasoning) | No data | 70.1% |
| Long-context reasoning (AA-LCR) | No data | 74.7% |
Independent evaluations by Artificial Analysis, run the same way for every model, at the reasoning setting shown. Percentages unless marked as an index.
Frequently asked questions
Should I choose Kimi K3.1 Pro or o3?
Choose Kimi K3.1 Pro for reused prompts and documents (RAG, agents), very long inputs and the latest release. Choose o3 for high-volume, cost-sensitive work and writing and code generation.
Which is cheaper, Kimi K3.1 Pro or o3?
o3 is 13% cheaper than Kimi K3.1 Pro at the headline price ($3.50 / 1M tokens vs $4.00 / 1M tokens).
Which has the larger context window, Kimi K3.1 Pro or o3?
Kimi K3.1 Pro reads more per request: 1.05M tokens against 200k.
What is the difference between Kimi K3.1 Pro and o3?
Kimi K3.1 Pro is made by Moonshot AI and o3 by OpenAI. o3 is 13% cheaper than Kimi K3.1 Pro at the headline price ($3.50 / 1M tokens vs $4.00 / 1M tokens). Kimi K3.1 Pro reads more per request: 1.05M tokens against 200k. Kimi K3.1 Pro is the newer model (Oct 23, 2026, against Apr 16, 2025). Only o3 offers batch api.
How much do Kimi K3.1 Pro and o3 cost per month?
At 20 million input and 5 million output tokens a month, Kimi K3.1 Pro costs $90.00 and o3 costs $80.00, at standard rates.
Which is newer, Kimi K3.1 Pro or o3?
Kimi K3.1 Pro was released on Oct 23, 2026 and o3 on Apr 16, 2025.