Compare

GPT-5.1-Codex-Mini vs Kimi K2.6 (free)

This page is context-first: how much text each model can take in one request. Full specs adds capabilities and limits; the pricing matrix below is only about $/million tokens from hosts that list both models.

Openai

Model

GPT-5.1-Codex-Mini

Image inputTool calling

Context window

400K

400,000 tokens · ~300K words

Model page
Moonshot

Model

Kimi K2.6 (free)

Image inputTool calling

Context window

262K

262,144 tokens · ~197K words

Model page

Context window · side by side

Bar length is relative to the larger of the two windows (100% = max of this pair). This is not pricing.

GPT-5.1-Codex-Mini400K
Kimi K2.6 (free)262K

GPT-5.1-Codex-Mini has about 1.5× the context window of the other in this pair.

GPT-5.1-Codex-Mini has 52% more context capacity (400K vs 262K tokens).

Quick verdicts

Short takeaways — validate with your own workloads.

  • Long document processing

    Use GPT-5.1-Codex-Mini. Its 400K context fits entire documents without chunking (vs 262K).

Full specs

Context, output, capabilities, and dates. Green highlights the favorable value where we compute a winner.

SpecGPT-5.1-Codex-MiniKimi K2.6 (free)
Context window400,000 tokens (400K)262,144 tokens (262K)
Max output tokens100,000 tokens (100K)N/A
Speed tierFastBalanced
VisionYesYes
Function callingYesYes
Extended thinkingYesYes
Prompt cachingYesNo
Batch APINoNo
Release dateNov 2025Apr 2026

Frequently asked questions

GPT-5.1-Codex-Mini has a larger context window: 400K tokens vs 262K. For long documents, large codebases, or extended agent sessions, the larger context window reduces the need to chunk inputs or summarize history.

Powered by Mem0

Use a smaller model.
Get better results.

Mem0 gives your AI long-term memory so you stop re-sending context on every call. That means you can use a smaller, faster, cheaper model — and still get better answers.

Example: a multi-turn chat session

Without Mem0~128K tokens sent
Full history
Repeated info
Old context
With Mem0~20K tokens sent
Key memories
Current turn

80% less to send — works with any model