Kimi K3.1 Pro vs o3
Kimi K3.1 Pro leads the LLM Stats Score 55.5 to 30.4. o3 is 1.1x cheaper per token.
Moonshot AI · OpenAI · Updated for 2026
Which is better?
Kimi K3.1 Pro leads the overall LLM Stats Score 55.5 to 30.4, ranking #5 overall.
In the 5 individual benchmarks reported for both models, Kimi K3.1 Pro wins 5; this is a narrower head-to-head signal than the composite indexes.
On price, o3 is roughly 1.1x cheaper per token on a blended 3:1 input/output basis, which adds up quickly at production volume.
Kimi K3.1 Pro also accepts a larger context window (1,048,576 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 Kimi K3.1 Pro
- overall performance matters — it scores 55.5 and ranks #5 on LLM Stats
- your work emphasizes reasoning and coding — it leads those capability indexes
- you value its reported benchmark strengths — it wins 5 of 5 exact shared results
- you process long inputs — it offers a 1,048,576 token context window
- you want the most recent training data — it shipped Oct 2026
Choose o3
- cost matters — it's about 1.1x cheaper per token
At a glance
The differences that matter most.
Capability indexes
Additional strengths measured across groups of related public benchmarks
Individual benchmarks
30 reported for Kimi K3.1 Pro · 22 for o3
Kimi K3.1 Pro outperforms in 5 benchmarks (BrowseComp, CharXiv-R, GPQA, Humanity's Last Exam, MMMU-Pro), while o3 is better at 0 benchmarks.
Kimi K3.1 Pro 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, Kimi K3.1 Pro ($2.00/1M tokens) costs the same as o3 ($2.00/1M tokens).
For output processing, Kimi K3.1 Pro ($10.00/1M tokens) is 1.3x more expensive than o3 ($8.00/1M tokens).
In conclusion, Kimi K3.1 Pro is more expensive than o3.*
* Using a 3:1 ratio of input to output tokens
Context Window
Maximum input and output token capacity
Kimi K3.1 Pro accepts 1,048,576 input tokens compared to o3's 200,000 tokens. Kimi K3.1 Pro can generate longer responses up to 1,048,576 tokens, while o3 is limited to 100,000 tokens.
Input capabilities
Documented input modalities across available providers
Both Kimi K3.1 Pro and o3 support multimodal inputs.
They are both capable of processing various types of data, offering versatility in application.
Kimi K3.1 Pro
o3
Release Timeline
When each model was launched
Kimi K3.1 Pro was released on 2026-10-23, while o3 was released on 2025-04-16.
Kimi K3.1 Pro is 19 months newer than o3.
Oct 23, 2026
1 weeks ago
1.5yr newerApr 16, 2025
1.5 years ago
Knowledge Cutoff
When training data ends
o3 has a documented knowledge cutoff of 2024-05-31, while Kimi K3.1 Pro's cutoff date is not specified.
We can confirm o3's training data extends to 2024-05-31, but cannot make a direct comparison without Kimi K3.1 Pro's cutoff date.
—
May 2024
Provider Availability
Kimi K3.1 Pro is available from Moonshot AI. o3 is available from OpenAI.
Kimi K3.1 Pro
o3
Outputs Comparison
Judge for yourself.
Run your own prompts against Kimi K3.1 Pro and o3 side-by-side, then vote on the output you prefer.
FAQ
Common questions about Kimi K3.1 Pro vs o3.