GPT-5.1 High vs Kimi K2.5
GPT-5.1 High and Kimi K2.5 are closely matched at 35.2 and 38.7 on the LLM Stats Score. Kimi K2.5 is 2.9x cheaper per token.
OpenAI · Moonshot AI · Updated for 2026
Which is better?
GPT-5.1 High and Kimi K2.5 are closely matched on the overall LLM Stats Score at 35.2 and 38.7.
In the 3 individual benchmarks reported for both models, GPT-5.1 High wins 3; this is a narrower head-to-head signal than the composite indexes.
On price, Kimi K2.5 is roughly 2.9x cheaper per token on a blended 3:1 input/output basis, which adds up quickly at production volume.
GPT-5.1 High also accepts a larger context window (400,000 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-5.1 High
- you value its reported benchmark strengths — it wins 3 of 3 exact shared results
- you process long inputs — it offers a 400,000 token context window
Choose Kimi K2.5
- cost matters — it's about 2.9x cheaper per token
- you want the most recent training data — it shipped Jan 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
3 reported for GPT-5.1 High · 40 for Kimi K2.5
GPT-5.1 High outperforms in 3 benchmarks (AIME 2025, GPQA, LiveBench), while Kimi K2.5 is better at 0 benchmarks.
GPT-5.1 High 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-5.1 High ($1.25/1M tokens) is 2.1x more expensive than Kimi K2.5 ($0.60/1M tokens).
For output processing, GPT-5.1 High ($10.00/1M tokens) is 3.3x more expensive than Kimi K2.5 ($3.00/1M tokens).
In conclusion, GPT-5.1 High is more expensive than Kimi K2.5.*
* Using a 3:1 ratio of input to output tokens
Context Window
Maximum input and output token capacity
GPT-5.1 High accepts 400,000 input tokens compared to Kimi K2.5's 262,100 tokens. Kimi K2.5 can generate longer responses up to 262,100 tokens, while GPT-5.1 High is limited to 128,000 tokens.
Input capabilities
Documented input modalities across available providers
Both GPT-5.1 High and Kimi K2.5 support multimodal inputs.
They are both capable of processing various types of data, offering versatility in application.
GPT-5.1 High
Kimi K2.5
License
Usage and distribution terms
GPT-5.1 High is licensed under a proprietary license, while Kimi K2.5 uses MIT.
License differences may affect how you can use these models in commercial or open-source projects.
Proprietary
Closed source
MIT
Open weights
Release Timeline
When each model was launched
GPT-5.1 High was released on 2025-11-12, while Kimi K2.5 was released on 2026-01-27.
Kimi K2.5 is 3 months newer than GPT-5.1 High.
Nov 12, 2025
10 months ago
Jan 27, 2026
8 months ago
2mo newerKnowledge Cutoff
When training data ends
Neither model specifies a knowledge cutoff date.
Unable to compare the recency of their training data.
Provider Availability
GPT-5.1 High is available from OpenAI. Kimi K2.5 is available from Fireworks, Moonshot AI.
GPT-5.1 High
Kimi K2.5
Outputs Comparison
Judge for yourself.
Run your own prompts against GPT-5.1 High and Kimi K2.5 side-by-side, then vote on the output you prefer.
FAQ
Common questions about GPT-5.1 High vs Kimi K2.5.