GPT-5.5 vs Kimi K3
Kimi K3 leads the LLM Stats Score 52.7 to 48.0. Kimi K3 is 2.0x cheaper per token.
OpenAI · Moonshot AI · Updated for 2026
Which is better?
Kimi K3 leads the overall LLM Stats Score 52.7 to 48.0, ranking #8 overall.
In the 9 individual benchmarks reported for both models, Kimi K3 wins 7; this is a narrower head-to-head signal than the composite indexes.
On price, Kimi K3 is roughly 2.0x cheaper per token on a blended 3:1 input/output basis, which adds up quickly at production volume.
GPT-5.5 also accepts a larger context window (1,050,000 input tokens), making it the stronger choice for long documents and large codebases.
Based on current LLM Stats indexes, shared benchmarks, pricing, and model metadata for 2026.
Choose GPT-5.5
- you process long inputs — it offers a 1,050,000 token context window
Choose Kimi K3
- overall performance matters — it scores 52.7 and ranks #8 on LLM Stats
- your work emphasizes agents — it leads those capability indexes
- you value its reported benchmark strengths — it wins 7 of 9 exact shared results
- cost matters — it's about 2.0x cheaper per token
- you want the most recent training data — it shipped Jul 2026
- you need open weights you can self-host or fine-tune
At a glance
The differences that matter most.
Capability indexes
Additional strengths measured across groups of related public benchmarks
Individual benchmarks
28 reported for GPT-5.5 · 31 for Kimi K3
GPT-5.5 outperforms in 2 benchmarks (GPQA, MMMU-Pro), while Kimi K3 is better at 7 benchmarks (BrowseComp, DeepSWE 1.1, FrontierSWE, Humanity's Last Exam, MCP Atlas, OfficeQA Pro, Toolathlon).
Kimi K3 significantly outperforms across most benchmarks.
Human preference
Blind head-to-head votes and playground preference scores
Pricing Analysis
Price comparison per million tokens
For input processing, GPT-5.5 ($5.00/1M tokens) is 1.8x more expensive than Kimi K3 ($2.85/1M tokens).
For output processing, GPT-5.5 ($30.00/1M tokens) is 2.1x more expensive than Kimi K3 ($14.25/1M tokens).
In conclusion, GPT-5.5 is more expensive than Kimi K3.*
* Using a 3:1 ratio of input to output tokens
Context Window
Maximum input and output token capacity
GPT-5.5 accepts 1,050,000 input tokens compared to Kimi K3's 1,048,576 tokens. Kimi K3 can generate longer responses up to 1,048,576 tokens, while GPT-5.5 is limited to 128,000 tokens.
Input capabilities
Documented input modalities across available providers
Both GPT-5.5 and Kimi K3 support multimodal inputs.
They are both capable of processing various types of data, offering versatility in application.
GPT-5.5
Kimi K3
License
Usage and distribution terms
GPT-5.5 is licensed under a proprietary license, while Kimi K3 uses Kimi K3 License.
License differences may affect how you can use these models in commercial or open-source projects.
Proprietary
Closed source
Kimi K3 License
Open weights
Release Timeline
When each model was launched
GPT-5.5 was released on 2026-04-23, while Kimi K3 was released on 2026-07-16.
Kimi K3 is 3 months newer than GPT-5.5.
Apr 23, 2026
5 months ago
Jul 16, 2026
2 months ago
2mo newerKnowledge Cutoff
When training data ends
GPT-5.5 has a documented knowledge cutoff of 2025-12-01, while Kimi K3's cutoff date is not specified.
We can confirm GPT-5.5's training data extends to 2025-12-01, but cannot make a direct comparison without Kimi K3's cutoff date.
Dec 2025
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Provider Availability
GPT-5.5 is available from OpenAI. Kimi K3 is available from DeepInfra, Fireworks, Moonshot AI, Novita, Together.
GPT-5.5
Kimi K3
Outputs Comparison
Judge for yourself.
Run your own prompts against GPT-5.5 and Kimi K3 side-by-side, then vote on the output you prefer.
FAQ
Common questions about GPT-5.5 vs Kimi K3.