text model comparison
GPT-5.5 vs Kimi K3
GPT-5.5 and Kimi K3 are both current text models, from OpenAI and Moonshot Kimi. Kimi K3 is 40% cheaper per 1M input tokens than GPT-5.5, $3 vs $5. On Arena Text, GPT-5.5 scores 1482 Elo and Kimi K3 1488 Elo (Arena, measured October 8, 2026). Both accept about 1.05M tokens of context (1,050,000 and 1,048,576).
- Higher Arena Text
- Kimi K31488 Elo against 1482 Elo
- Lower price per 1M input tokens
- Kimi K3$3 against $5
- Longer context window
- GPT-5.51.05M tokens against 1.05M tokens
- Newer release
- Kimi K3Jul 2026 against Apr 2026
Data verified October 28, 2026 · Dataset 2026-10-28
Side by side
GPT-5.5 and Kimi K3, 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 | GPT-5.5 | Kimi K3 |
|---|---|---|
| Price | ||
| Price per 1M input tokens | $5 | $3 (better) |
| Price per 1M output tokens | $30 | $15 (better) |
| Independent benchmarks | ||
| Arena Text | 1482 Elo (#14 of 49) | 1488 Elo (#8 of 49) (better) |
| GPQA Diamond | 90.7% (#23 of 40) | 93.1% (#15 of 40) (better) |
| FrontierMath Tiers 1-3 (v2) | 85.3% (#11 of 40) (better) | 72.2% (#19 of 40) |
| SimpleQA Verified | 63% (#13 of 36) (better) | 50.6% (#19 of 36) |
| LiveBench Overall | 79.91 points (#1 of 5) | Not measured |
| Specs | ||
| Provider | OpenAI | Moonshot Kimi |
| Release date | April 23, 2026 | July 16, 2026 |
| Access | API only | API and open weights |
| Context window | 1,050,000 tokens | 1,048,576 tokens |
| Max output | 128,000 tokens | Not reported |
| Input | text, image | text, image |
| Output | text | text |
Scores:Arena · 2026-10-12Epoch AI · 2026-10-12LiveBench · 2026-06-25
Charts
Against every current text model
Where GPT-5.5 and Kimi K3 land among the current models of their task, on every independent benchmark, on price and on context.
Where each stands
On Arena Text, GPT-5.5 ranks #14 and Kimi K3 #8 of 49 current models. Each bar is the share of current models it beats: on score, price and context.
Independent benchmarks
Arena Text
GPT-5.5:#14of 49
1,482 Elo · ahead of 71%
Kimi K3:#8of 49
1,488 Elo · ahead of 85%
GPQA Diamond
GPT-5.5:#23of 40
90.7% · ahead of 44%
Kimi K3:#15of 40
93.1% · ahead of 64%
FrontierMath Tiers 1-3 (v2)
GPT-5.5:#11of 40
85.3% · ahead of 74%
Kimi K3:#19of 40
72.2% · ahead of 54%
SimpleQA Verified
GPT-5.5:#13of 36
63% · ahead of 66%
Kimi K3:#19of 36
50.6% · ahead of 49%
LiveBench Overall
GPT-5.5:#1of 5
79.9 · ahead of 100%
Kimi K3: Not scored
Price and context
Price per 1M input tokens
GPT-5.5:#45of 51
$5 · cheaper than 8%
Kimi K3:#41of 51
$3 · cheaper than 20%
Price per 1M output tokens
GPT-5.5:#47of 51
$30 · cheaper than 8%
Kimi K3:#40of 51
$15 · cheaper than 20%
Context window
GPT-5.5:#1of 66
1.05M tokens · longer than 86%
Kimi K3:#11of 66
1.05M tokens · longer than 65%
Quality against price
GPT-5.5 scores 1,482 at $11.25; Kimi K3 scores 1,488 at $6 (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 Argon | $4 | 1,525 | |
| Claude Opus 5.5 | Anthropic | $8 | 1,507 |
| Claude Fable 5 | Anthropic | $20 | 1,504 |
| Claude Fable 5.1 | Anthropic | $20 | 1,501 |
| Gemini 3.8 Flash | $1.50 | 1,497 | |
| Muse Spark 1.3 | Meta | $2 | 1,494 |
| Claude Opus 5 | Anthropic | $10 | 1,490 |
| Kimi K3 | Moonshot Kimi | $6 | 1,488 |
| Gemini 3.7 Flash | $1.50 | 1,486 | |
| GPT-5.6 Sol | OpenAI | $8 | 1,485 |
| GPT-6.1 Sol | OpenAI | $4 | 1,484 |
| Qwen3.8-Max | Alibaba Qwen | $3 | 1,483 |
| GPT-5.5 | OpenAI | $11 | 1,482 |
| Gemini 3.6 Flash | $3 | 1,482 | |
| Claude Opus 4.8 | Anthropic | $10 | 1,481 |
| MiMo-V2.6-Pro | Xiaomi MiMo | $0.54 | 1,480 |
| GLM-5.3 | Z.ai | $2.15 | 1,478 |
| Claude Sonnet 5.5 | Anthropic | $4 | 1,476 |
| GPT-5.4 | OpenAI | $5.63 | 1,475 |
| GPT-6 Astra | OpenAI | $20 | 1,475 |
| DeepSeek-V4.1-Flash | DeepSeek | $0.52 | 1,475 |
| GLM-5.3-Flash | Z.ai | $0.24 | 1,475 |
| Gemini 3 Flash Preview | $1.13 | 1,473 | |
| Grok 4.20 | xAI | $1.56 | 1,472 |
| GPT-5.6 Terra | OpenAI | $4.50 | 1,466 |
| Grok 4.5 | xAI | $3 | 1,466 |
| DeepSeek-V4-Pro | DeepSeek | $1.98 | 1,465 |
| Claude Sonnet 5 | Anthropic | $4 | 1,461 |
| GPT-6 Sol | OpenAI | $4 | 1,456 |
| Gemini 3.5 Flash-Lite | $0.85 | 1,455 | |
| Grok 4.6 | xAI | $3 | 1,454 |
| GPT-5.6 Luna | OpenAI | $0.45 | 1,452 |
| MiMo-V2.6-Flash | Xiaomi MiMo | $0.18 | 1,451 |
| GPT-6 Luna | OpenAI | $0.20 | 1,443 |
| Grok 4.7 | xAI | $3 | 1,443 |
| Grok 4.3 | xAI | $1.56 | 1,442 |
| Mistral Large 4 | Mistral AI | $2.06 | 1,429 |
| GPT-4.1 | OpenAI | $3.50 | 1,415 |
| Solar Pro 4 | Upstage | $0.52 | 1,386 |
| 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, GPT-5.5 costs 1.8 times as much as Kimi K3, at each provider's listed rates.
10M input and 2M output tokens
GPT-5.5 costs 1.8× as much
- GPT-5.5
- $110
- Kimi K3
- $60
The same, with 9M of the input tokens cached
GPT-5.5 costs 1.9× as much
- GPT-5.5
- $69.50
- Kimi K3
- $35.70
| Workload or rate | GPT-5.5 | Kimi K3 |
|---|---|---|
| Example workloads | ||
| 10M input and 2M output tokens | $110 | $60 (better) |
| The same, with 9M of the input tokens cached | $69.50 | $35.70 (better) |
| Other listed rates | ||
| 1M input tokens, cached | $0.50 | $0.30 (better) |
Verdict
When to choose each
GPT-5.5
Where it leads
- Higher FrontierMath Tiers 1-3 (v2) score, 85.3% vs 72.2%
- Higher SimpleQA Verified score, 63% vs 50.6%
Best for
- High-capability API evaluations with long context
Watch out for
- Prompts above the provider long-context threshold use higher token rates; validate the selected reasoning effort against production cost
Kimi K3
Where it leads
- Lower input and output prices, $3 and $15 vs $5 and $30 per 1M tokens
- Higher Arena Text score, 1488 Elo vs 1482 Elo
- Higher GPQA Diamond score, 93.1% vs 90.7%
- Open weights you can run yourself
- Cheaper cached input, $0.30 vs $0.50 per 1M tokens
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
From benchmark to production
Building on GPT-5.5 or Kimi K3?
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.
FAQ
GPT-5.5 vs Kimi K3 FAQ
Which is cheaper, GPT-5.5 or Kimi K3?
Kimi K3 is 40% cheaper per 1M input tokens than GPT-5.5, $3 vs $5. For 10M input and 2M output tokens, GPT-5.5 costs $110 and Kimi K3 $60 at standard rates.
Which is cheaper with prompt caching, GPT-5.5 or Kimi K3?
GPT-5.5 charges $0.50 per 1M cached input tokens, 90% below its standard input rate, and Kimi K3 $0.30, 90% below. With 9M of 10M input tokens cached and 2M output tokens, GPT-5.5 costs $69.50 and Kimi K3 $35.70.
Which scores higher on independent benchmarks, GPT-5.5 or Kimi K3?
Kimi K3 leads on Arena Text, 1488 Elo to 1482 Elo; Kimi K3 leads on GPQA Diamond, 93.1% to 90.7%; GPT-5.5 leads on FrontierMath Tiers 1-3 (v2), 85.3% to 72.2%. Scores are independent evaluations, not either vendor's launch figures.
Which has the larger context window, GPT-5.5 or Kimi K3?
Both accept about 1.05M tokens of context (1,050,000 and 1,048,576).
Can I run GPT-5.5 or Kimi K3 myself?
Kimi K3 is released as open weights you can run yourself; GPT-5.5 is available through its provider's API only.
Further reading
More on GPT-5.5 and Kimi K3
Articles on GPT-5.5 and Kimi K3
Related comparisons
- Claude Opus 4.8 vs GPT-5.5
- Claude Opus 5.5 vs Kimi K3
- Gemini 3.5 Flash vs GPT-5.5
- GPT-6 Luna vs Kimi K3
- Claude Opus 5.5 vs GPT-5.5
- Gemini 3.8 Flash vs Kimi K3
- GPT-5.5 vs GPT-6 Astra
- Claude Opus 5 vs Kimi K3
- Gemini 3.8 Flash vs GPT-5.5
- Claude Opus 4.8 vs Kimi K3
- Claude Opus 5 vs GPT-5.5
- Claude Sonnet 5 vs Kimi K3
Production evaluation
Choosing between GPT-5.5 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