# Gemini 4 Argon vs Kimi K3.1 Pro

Gemini 4 Argon and Kimi K3.1 Pro charge the same per token: $2 per million tokens read and $10 per million written. The bill can still differ, because the same text can be a different number of tokens on each. Below are both price lists, 8 everyday jobs priced on each, and the count for one text.

- Page, with a calculator for your own job: https://tecyfy.com/prices/compare/gemini-4-argon-vs-kimi-k3-1-pro
- Makers: Gemini 4 Argon from Google, Kimi K3.1 Pro from Moonshot AI

## Price per million tokens, in US dollars

| | Gemini 4 Argon | Kimi K3.1 Pro |
| --- | --: | --: |
| Input | $2 | $2 |
| Cached input | $0.10 | $0.20 |
| Cache write | not listed | $2 |
| Output | $10 | $10 |
| Blend, 3 read for each 1 written | $4 | $4 |
| Batch input | not listed | not listed |
| Batch output | not listed | not listed |
| Context window, tokens | not listed | 1.05M |
| Capability score (Epoch Capabilities Index; GPT-5 is 150) | 165 | not listed |
| Longest answer, tokens | not listed | not listed |

Gemini 4 Argon: Until 30 November 2026. From 1 December 2026 it is $4 in, $20 out and $0.20 cached.

## The same text, counted by each maker

Our lesson "How AI writes" (https://tecyfy.com/learn/how-ai-works/how-ai-writes), about 1,700 words of English:

- Gemini 4 Argon: about 2,200 tokens. Google does not publish the Gemini tokenizer. Its rule is that a token is about 4 characters, so the count is the characters divided by 4.
- Kimi K3.1 Pro: about 2,100 tokens. Counted with the tokenizer Moonshot AI publishes with Kimi K3, the model its API serves.

## What 8 everyday jobs cost a month on each

Each job at its usual runs a day, for 30 days, at the standard price.

| Job | Tokens in, out, runs a day | Gemini 4 Argon | Kimi K3.1 Pro |
| --- | --- | --: | --: |
| A chat question | 300, 500, 100 | $16.80 | $16.80 |
| A hard question, with thinking | 300, 1,400, 100 | $43.80 | $43.80 |
| A long report, summarised | 60,000, 2,000, 20 | $84.00 | $84.00 |
| A 40-turn agent task | 2,800,000, 40,000, 10 | $364 | $439 |
| A support bot's reply | 4,000, 300, 2,000 | $432 | $444 |
| Sort a message into a category | 250, 5, 50,000 | $825 | $825 |
| Read an invoice into fields | 1,500, 250, 1,000 | $165 | $165 |
| Review a pull request | 25,000, 4,500, 50 | $143 | $143 |

## Questions

### Which is cheaper, Gemini 4 Argon or Kimi K3.1 Pro?

Per token, neither: both charge $2 per million tokens read and $10 per million written. The same text can still be a different number of tokens on each, so the bills can differ.

### Which is better, Gemini 4 Argon or Kimi K3.1 Pro?

Gemini 4 Argon scores 165 on the Epoch Capabilities Index, an independent score from Epoch AI that combines over 50 benchmarks (GPT-5 is 150). Kimi K3.1 Pro has no independent score yet, so the only fair test is to run the same 10 tasks on both.

### What does a support bot cost a month on Gemini 4 Argon and Kimi K3.1 Pro?

At 2,000 replies a day, each reading 4,000 tokens (50 percent of them from cache) and writing 300, it costs $432 a month on Gemini 4 Argon and $444 on Kimi K3.1 Pro: Kimi K3.1 Pro costs 1 times as much for this job.

### What does an AI agent task cost on Gemini 4 Argon and Kimi K3.1 Pro?

One 40-turn task that reads 2,800,000 tokens in all, 90 percent of them from cache, and writes 40,000, costs $1.21 on Gemini 4 Argon and $1.46 on Kimi K3.1 Pro. At 10 tasks a day that is $364 and $439 a month.

### Does the same text take the same number of tokens on Gemini 4 Argon and Kimi K3.1 Pro?

No. Our lesson "How AI writes", 1,700 words long, is about 2,200 tokens on Gemini 4 Argon and about 2,100 on Kimi K3.1 Pro. Each maker cuts text its own way, and every extra token is paid for at the model's price.

### Can I pay less on Gemini 4 Argon and Kimi K3.1 Pro for work that can wait?

Not with a batch price: neither maker's price page lists one for these models. A cache still lowers the price of text the model reads again.

## Sources

- [Google: API prices](https://ai.google.dev/gemini-api/docs/pricing)
- [Moonshot AI: API prices](https://platform.kimi.ai/docs/pricing/chat)
- [Epoch Capabilities Index, by Epoch AI (CC BY 4.0)](https://epoch.ai/benchmarks/eci)

## Other comparisons

- [Gemini 3.6 Flash vs Gemini 4 Argon](https://tecyfy.com/prices/compare/gemini-3-6-flash-vs-gemini-4-argon.md)
- [Gemini 3.1 Pro Preview vs Gemini 4 Argon](https://tecyfy.com/prices/compare/gemini-3-1-pro-preview-vs-gemini-4-argon.md)
- [Gemini 3.1 Flash-Lite vs Gemini 4 Argon](https://tecyfy.com/prices/compare/gemini-3-1-flash-lite-vs-gemini-4-argon.md)
- [Gemini 3 Flash Preview vs Gemini 4 Argon](https://tecyfy.com/prices/compare/gemini-3-flash-preview-vs-gemini-4-argon.md)
- [Gemini 2.5 Pro vs Gemini 4 Argon](https://tecyfy.com/prices/compare/gemini-2-5-pro-vs-gemini-4-argon.md)
- [Gemini 2.5 Flash vs Gemini 4 Argon](https://tecyfy.com/prices/compare/gemini-2-5-flash-vs-gemini-4-argon.md)