text model comparison
Gemini 3.8 Flash vs Kimi K3.1 Pro
Gemini 3.8 Flash and Kimi K3.1 Pro are both current text models, from Google and Moonshot Kimi. Gemini 3.8 Flash is 63% cheaper per 1M input tokens than Kimi K3.1 Pro, $0.75 vs $2. On Arena Text, Gemini 3.8 Flash scores 1497 Elo and Kimi K3.1 Pro 1485 Elo (Arena, measured November 11, 2026). Both accept 1,048,576 tokens of context.
- Higher Arena Text
- Gemini 3.8 Flash1497 Elo against 1485 Elo
- Lower price per 1M input tokens
- Gemini 3.8 Flash$0.75 against $2
- Newer release
- Kimi K3.1 ProOct 2026 against Sep 2026
Data verified November 15, 2026 · Dataset 2026-11-15
Side by side
Gemini 3.8 Flash and Kimi K3.1 Pro, line by line
Prices in effect today, compared at the same tier wherever both list one. The better value in each row is highlighted.
| Fact | Gemini 3.8 Flash | Kimi K3.1 Pro |
|---|---|---|
| Price | ||
| Price per 1M input tokens | $0.75 (better) | $2 |
| Price per 1M output tokens | $3.75 (better) | $10 |
| Independent benchmarks | ||
| Arena Text | 1497 Elo (#5 of 50) (better) | 1485 Elo (#10 of 50) |
| Arena WebDev | 1583 Elo (#28 of 45) | 1687 Elo (#8 of 45) (better) |
| GPQA Diamond | 95.4% (#5 of 40) (better) | 94.2% (#10 of 40) |
| FrontierMath Tiers 1-3 (v2) | 68.4% (#25 of 39) | 78.2% (#17 of 39) (better) |
| SimpleQA Verified | 69.7% (#8 of 36) (better) | 62.2% (#13 of 36) |
| Specs | ||
| Provider | Moonshot Kimi | |
| Release date | September 2, 2026 | October 23, 2026 |
| Access | API only | API and open weights |
| Context window | 1,048,576 tokens | 1,048,576 tokens |
| Max output | 65,536 tokens | 1,048,576 tokens |
| Input | text, image, audio, video | text, image, video |
| Output | text | text |
Charts
Against every current text model
Where Gemini 3.8 Flash and Kimi K3.1 Pro land among the current models of their task, on every independent benchmark, on price and on context.
Where each stands
On Arena Text, Gemini 3.8 Flash ranks #5 and Kimi K3.1 Pro #10 of 50 current models. Each bar is the share of current models it beats: on score, price and context.
Independent benchmarks
Arena Text
Gemini 3.8 Flash:#5of 50
1,497 Elo · ahead of 90%
Kimi K3.1 Pro:#10of 50
1,485 Elo · ahead of 80%
Arena WebDev
Gemini 3.8 Flash:#28of 45
1,583 Elo · ahead of 39%
Kimi K3.1 Pro:#8of 45
1,687 Elo · ahead of 84%
GPQA Diamond
Gemini 3.8 Flash:#5of 40
95.4% · ahead of 87%
Kimi K3.1 Pro:#10of 40
94.2% · ahead of 77%
FrontierMath Tiers 1-3 (v2)
Gemini 3.8 Flash:#25of 39
68.4% · ahead of 37%
Kimi K3.1 Pro:#17of 39
78.2% · ahead of 58%
SimpleQA Verified
Gemini 3.8 Flash:#8of 36
69.7% · ahead of 77%
Kimi K3.1 Pro:#13of 36
62.2% · ahead of 66%
Price and context
Price per 1M input tokens
Gemini 3.8 Flash:#23of 58
$0.75 · cheaper than 61%
Kimi K3.1 Pro:#34of 58
$2 · cheaper than 23%
Price per 1M output tokens
Gemini 3.8 Flash:#27of 58
$3.75 · cheaper than 54%
Kimi K3.1 Pro:#39of 58
$10 · cheaper than 25%
Context window
Gemini 3.8 Flash:#12of 68
1.05M tokens · longer than 61%
Kimi K3.1 Pro:#12of 68
1.05M tokens · longer than 61%
Quality against price
Gemini 3.8 Flash scores 1,497 at $1.50; Kimi K3.1 Pro scores 1,485 at $4 (blended price per 1M tokens). The line joins the current models no other beats on both price and Arena Text score; hover any point to name it.
Quality against price: the data
| Model | Provider | Blended price per 1M tokens | Arena Text (Elo) |
|---|---|---|---|
| Gemini 4 Carbon | $4 | 1,526 | |
| Gemini 4 Argon | $4 | 1,522 | |
| Muse Wonder | Meta | $8 | 1,511 |
| Claude Opus 5.5 | Anthropic | $8 | 1,507 |
| Gemini 3.8 Flash | $1.50 | 1,497 | |
| Muse Spark 1.3 | Meta | $2 | 1,497 |
| Gemini 4 Hydrogen | $3 | 1,490 | |
| Kimi K3 | Moonshot Kimi | $6 | 1,487 |
| GPT-5.6 Sol | OpenAI | $8 | 1,485 |
| Kimi K3.1 Pro | Moonshot Kimi | $4 | 1,485 |
| Qwen3.8-Max | Alibaba Qwen | $3 | 1,484 |
| Gemini 3.6 Flash | $3 | 1,483 | |
| GLM-5.3 | Z.ai | $2.15 | 1,482 |
| GPT-5.5 | OpenAI | $11 | 1,481 |
| GPT-6.1 Sol | OpenAI | $4 | 1,481 |
| MiMo-V2.6-Pro | Xiaomi MiMo | $0.54 | 1,480 |
| GPT-5.4 | OpenAI | $5.63 | 1,475 |
| DeepSeek-V4.1-Flash | DeepSeek | $0.52 | 1,475 |
| GLM-5.3-Flash | Z.ai | $0.24 | 1,475 |
| GPT-6 Astra | OpenAI | $20 | 1,474 |
| Gemini 3 Flash Preview | $1.13 | 1,473 | |
| Claude Sonnet 5.5 | Anthropic | $4 | 1,473 |
| Grok 4.20 | xAI | $1.56 | 1,472 |
| GPT-5.6 Terra | OpenAI | $4.50 | 1,468 |
| Grok 4.5 | xAI | $3 | 1,466 |
| DeepSeek-V4-Pro | DeepSeek | $1.98 | 1,464 |
| Grok 4.6 | xAI | $3 | 1,457 |
| GPT-6 Sol | OpenAI | $4 | 1,457 |
| Gemini 3.5 Flash-Lite | $0.85 | 1,455 | |
| GPT-5.6 Luna | OpenAI | $0.45 | 1,453 |
| Step 5 Preview | StepFun | $1.43 | 1,449 |
| MiMo-V2.6-Flash | Xiaomi MiMo | $0.18 | 1,448 |
| Grok 4.7 | xAI | $3 | 1,443 |
| Grok 4.3 | xAI | $1.56 | 1,442 |
| GPT-6 Luna | OpenAI | $0.20 | 1,441 |
| Claude Haiku 5.5 | Anthropic | $0.20 | 1,421 |
| Mistral Large 4 | Mistral AI | $1.05 | 1,420 |
| GPT-4.1 | OpenAI | $3.50 | 1,415 |
| Inkling 2 Small | Thinking Machines Lab | $0.47 | 1,412 |
| Solar Pro 4 | Upstage | $0.52 | 1,387 |
| GPT-4.1 mini | OpenAI | $0.70 | 1,383 |
| GPT-4.1 nano | OpenAI | $0.18 | 1,322 |
Cost
What each costs
Example workloads at each provider's listed rates, then every other rate either one lists. The cheaper figure in each row is highlighted.
The same work, priced
For 10M input and 2M output tokens, Kimi K3.1 Pro costs 2.7 times as much as Gemini 3.8 Flash, at each provider's listed rates.
10M input and 2M output tokens
Kimi K3.1 Pro costs 2.7× as much
- Gemini 3.8 Flash
- $15
- Kimi K3.1 Pro
- $40
The same, with 9M of the input tokens cached
Kimi K3.1 Pro costs 2.7× as much
- Gemini 3.8 Flash
- $8.93
- Kimi K3.1 Pro
- $23.80
| Workload or rate | Gemini 3.8 Flash | Kimi K3.1 Pro |
|---|---|---|
| Example workloads | ||
| 10M input and 2M output tokens | $15 (better) | $40 |
| The same, with 9M of the input tokens cached | $8.93 (better) | $23.80 |
| The same, through the batch API | $7.50 | Not listed |
| Other listed rates | ||
| 1M input tokens, cached | $0.075 (better) | $0.20 |
| 1M input tokens, 5-minute cache write | Not listed | $2 |
| 1M input tokens, 1-hour cache write | Not listed | $4 |
| 1M input tokens, batch | $0.375 | Not listed |
| 1M output tokens, batch | $1.875 | Not listed |
| 1M input tokens, Highspeed endpoint | Not listed | $4 |
| 1M output tokens, Highspeed endpoint | Not listed | $20 |
| 1M input tokens, priority | $1.35 | Not listed |
| 1M output tokens, priority | $6.75 | Not listed |
Your own bill will differ. These figures use list prices and example workloads. The AI Model Cost Audit reviews your real usage, shortlists models that score as well for each task for less, and estimates the savings.
Launch price $100, regular price $150
Verdict
When to choose each
Gemini 3.8 Flash
Where it leads
- Lower input and output prices, $0.75 and $3.75 vs $2 and $10 per 1M tokens
- Higher Arena Text score, 1497 Elo vs 1485 Elo
- Higher GPQA Diamond score, 95.4% vs 94.2%
- Higher SimpleQA Verified score, 69.7% vs 62.2%
- Accepts audio input
- Cheaper cached input, $0.075 vs $0.20 per 1M tokens
- Batch pricing, $0.375 input and $1.875 output per 1M tokens
Best for
- High-volume agentic and coding workloads where per-token cost dominates the decision
- Multimodal pipelines that need audio, video and PDF input in one model
Watch out for
- The listed price is promotional and ends 31 December 2026; on 1 January 2027 input and output both double, to $1.50 and $7.50, and cached input goes from $0.075 to $0.15
- Output pricing is billed inclusive of thinking tokens, so reasoning-heavy prompts cost more than the output length suggests
- Google’s published comparisons are against its own previous Flash release and were not independently reproduced here
- Google now points Gemini 3.8 Flash users to Gemini 4 Hydrogen, released November 12, 2026, as the recommended upgrade, with migration guidance
Kimi K3.1 Pro
Where it leads
- Higher Arena WebDev score, 1687 Elo vs 1583 Elo
- Higher FrontierMath Tiers 1-3 (v2) score, 78.2% vs 68.4%
- Longer responses, up to 1,048,576 vs 65,536 output tokens
- Open weights you can run yourself
Best for
- Long-horizon coding and agent work at mid-tier prices
- Long documents, images and video in one 1M-token context
Watch out for
- Thinking is always on: reasoning effort runs low, high or max, and max is the default
- The Highspeed endpoint, two to three times faster by Moonshot's account, costs twice as much at $4 input and $20 output per 1M tokens
- The weights carry Moonshot's own license: a model-as-a-service business above $20M in yearly revenue needs a separate agreement, and products above 100M monthly users or $20M monthly revenue must display the Kimi K3.1 Pro name
- Self-hosting takes a multi-node GPU cluster: the MXFP4 weights alone are about 1.56 TB
- Arena Text rates it 1485 on 3,995 votes (November 11, 2026), below Gemini 4 Carbon (1526) and Gemini 4 Hydrogen (1490)
From benchmark to production
Building on Gemini 3.8 Flash or Kimi K3.1 Pro?
Public scores rarely hold on your own data. We test both models on your real tasks, then build the agent or pipeline around the one that wins.
AI Model Cost AuditLaunch price $100, regular price $150
FAQ
Gemini 3.8 Flash vs Kimi K3.1 Pro FAQ
Which is cheaper, Gemini 3.8 Flash or Kimi K3.1 Pro?
Gemini 3.8 Flash is 63% cheaper per 1M input tokens than Kimi K3.1 Pro, $0.75 vs $2. For 10M input and 2M output tokens, Gemini 3.8 Flash costs $15 and Kimi K3.1 Pro $40 at standard rates.
Which is cheaper with prompt caching, Gemini 3.8 Flash or Kimi K3.1 Pro?
Gemini 3.8 Flash charges $0.075 per 1M cached input tokens, 90% below its standard input rate, and Kimi K3.1 Pro $0.20, 90% below. With 9M of 10M input tokens cached and 2M output tokens, Gemini 3.8 Flash costs $8.93 and Kimi K3.1 Pro $23.80.
Which scores higher on independent benchmarks, Gemini 3.8 Flash or Kimi K3.1 Pro?
Gemini 3.8 Flash leads on Arena Text, 1497 Elo to 1485 Elo; Kimi K3.1 Pro leads on Arena WebDev, 1687 Elo to 1583 Elo; Gemini 3.8 Flash leads on GPQA Diamond, 95.4% to 94.2%. Scores are independent evaluations, not either vendor's launch figures.
Which has the larger context window, Gemini 3.8 Flash or Kimi K3.1 Pro?
Both accept 1,048,576 tokens of context. Kimi K3.1 Pro returns up to 1,048,576 tokens per response, Gemini 3.8 Flash 65,536.
How do Gemini 3.8 Flash and Kimi K3.1 Pro differ in features?
Gemini 3.8 Flash takes text, image, audio and video input; Kimi K3.1 Pro takes text, image and video.
Can I run Gemini 3.8 Flash or Kimi K3.1 Pro myself?
Kimi K3.1 Pro is released as open weights you can run yourself; Gemini 3.8 Flash is available through its provider's API only.
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More on Gemini 3.8 Flash and Kimi K3.1 Pro
Articles on Gemini 3.8 Flash and Kimi K3.1 Pro
- Kimi K3.1 Pro: Benchmarks, Price and Should You Switch?October 25, 2026
- Gemini 3.8 Flash TTS: Price, Rankings and the Fine PrintSeptember 25, 2026
Related comparisons
- Claude Haiku 5.5 vs Gemini 3.8 Flash
- Gemini 4 Carbon vs Kimi K3.1 Pro
- Gemini 3.8 Flash vs Gemini 4 Argon
- Claude Opus 5.5 vs Kimi K3.1 Pro
- Gemini 3.8 Flash vs GPT-6.1 Sol
- Claude Sonnet 5.5 vs Kimi K3.1 Pro
- Claude Sonnet 5.5 vs Gemini 3.8 Flash
- Claude Sonnet 5 vs Kimi K3.1 Pro
- Claude Opus 5.5 vs Gemini 3.8 Flash
- DeepSeek-V4.1-Flash vs Kimi K3.1 Pro
- DeepSeek-V4.1-Flash vs Gemini 3.8 Flash
- Gemini 4 Argon vs Kimi K3.1 Pro
Production evaluation
Choosing between Gemini 3.8 Flash and Kimi K3.1 Pro?
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