High-volume, cost-sensitive work
Choose Kimi K3.1 Pro
Kimi K3.1 Pro costs 9% less on a typical mix of three input tokens for every output token ($4.00 against $4.38 per million tokens).
GPT-4o vs Kimi K3.1 Pro: price, context and capabilities
Choose Kimi K3.1 Pro for high-volume, cost-sensitive work, reused prompts and documents (RAG, agents), very long inputs and the latest release; on the other points the two are level or the data is missing.
In short
- Kimi K3.1 Pro is 9% cheaper than GPT-4o at the headline price ($4.00 / 1M tokens vs $4.38 / 1M tokens).
- Kimi K3.1 Pro reads more per request: 1.05M tokens against 128k.
- Kimi K3.1 Pro is the newer model (Oct 23, 2026, against May 13, 2024).
- Only GPT-4o offers batch api.
- Only Kimi K3.1 Pro offers reasoning.
Which should you choose?
Each answer below comes straight from the published prices, specifications and independent benchmark results.
Reused prompts and documents (RAG, agents)
Choose Kimi K3.1 Pro
Kimi K3.1 Pro charges $0.20 per million cached input tokens, against $1.25 for GPT-4o.
Very long inputs
Choose Kimi K3.1 Pro
Kimi K3.1 Pro reads up to 1.05M tokens per request, against 128k for GPT-4o.
Latest release
Choose Kimi K3.1 Pro
Kimi K3.1 Pro is the newer release (Oct 23, 2026, against May 13, 2024 for GPT-4o).
Monthly cost at three volumes
| Volume | GPT-4o | Kimi K3.1 Pro | Difference |
|---|---|---|---|
| Prototype: 1M input, 250K output tokens | $5.00 | $4.50 | Kimi K3.1 Pro, $0.50 less |
| Production: 20M input, 5M output tokens | $100.00 | $90.00 | Kimi K3.1 Pro, $10.00 less |
| Scale: 500M input, 100M output tokens | $2,250 | $2,000 | Kimi K3.1 Pro, $250.00 less |
Standard rates, without caching or batch discounts. Volumes are per month.
Specifications side by side
| GPT-4o | Kimi K3.1 Pro | |
|---|---|---|
| Provider | OpenAI | Moonshot AI |
| Category | Language models | Language models |
| Status | Deprecated | Generally available |
| Headline price | $4.38 / 1M tokens | $4.00 / 1M tokens |
| Input | $2.50 / 1M tokens | $2.00 / 1M tokens |
| Output | $10.00 / 1M tokens | $10.00 / 1M tokens |
| Cached input | $1.25 / 1M tokens | $0.20 / 1M tokens |
| Context window | 128k | 1.05M |
| Max output | 16k | 944k |
| Released | May 13, 2024 | Oct 23, 2026 |
| Knowledge cutoff | October 2023 | No data |
| Licence | Proprietary | Proprietary |
| Capabilities | Vision, Tool calling, Structured output, Prompt caching, Batch API | Vision, Reasoning, Tool calling, Structured output, Prompt caching |
| API model id | gpt-4o | kimi-k3.1-pro |
Benchmarks side by side
Leader in bold.
| Benchmark | GPT-4o | Kimi K3.1 Pro |
|---|---|---|
| Terminal-Bench Hard | 8.3% | No data |
| GPQA Diamond | 54.3% | No data |
| Humanity's Last Exam | 2.4% | No data |
| IFBench (instruction following) | 34.3% | No data |
| τ²-Bench (agentic tool use) | 25.1% | No data |
| Long-context reasoning (AA-LCR) | 49.3% | No data |
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 GPT-4o or Kimi K3.1 Pro?
Choose Kimi K3.1 Pro for high-volume, cost-sensitive work, reused prompts and documents (RAG, agents), very long inputs and the latest release; on the other points the two are level or the data is missing.
Which is cheaper, GPT-4o or Kimi K3.1 Pro?
Kimi K3.1 Pro is 9% cheaper than GPT-4o at the headline price ($4.00 / 1M tokens vs $4.38 / 1M tokens).
Which has the larger context window, GPT-4o or Kimi K3.1 Pro?
Kimi K3.1 Pro reads more per request: 1.05M tokens against 128k.
What is the difference between GPT-4o and Kimi K3.1 Pro?
GPT-4o is made by OpenAI and Kimi K3.1 Pro by Moonshot AI. Kimi K3.1 Pro is 9% cheaper than GPT-4o at the headline price ($4.00 / 1M tokens vs $4.38 / 1M tokens). Kimi K3.1 Pro reads more per request: 1.05M tokens against 128k. Kimi K3.1 Pro is the newer model (Oct 23, 2026, against May 13, 2024). Only GPT-4o offers batch api. Only Kimi K3.1 Pro offers reasoning.
How much do GPT-4o and Kimi K3.1 Pro cost per month?
At 20 million input and 5 million output tokens a month, GPT-4o costs $100.00 and Kimi K3.1 Pro costs $90.00, at standard rates.
Which is newer, GPT-4o or Kimi K3.1 Pro?
Kimi K3.1 Pro was released on Oct 23, 2026 and GPT-4o on May 13, 2024.