AI Model Release Tracker - Timeline of Major AI Models from 2022-2026

Kimi K1.5 vs GPT-5.3-Codex-Spark

Moonshot AI
Kimi K1.5
OpenAI
GPT-5.3-Codex-Spark
Overview
CompanyMoonshot AIOpenAI
Release dateJan 20 2025Feb 12 2026
AccessProprietaryProprietary
Specifications
Context window
128k
128k
Timeline
Release gapKimi K1.5 shipped 388 days before GPT-5.3-Codex-Spark

Which is better: Kimi K1.5 or GPT-5.3-Codex-Spark?

Kimi K1.5 and GPT-5.3-Codex-Spark don't publish scores on any of the same benchmarks, so there's no direct head-to-head comparison. Kimi K1.5 shipped 388 days before GPT-5.3-Codex-Spark, so benchmark comparisons should account for the intervening progress.

Context windows are 128k (Kimi K1.5) vs 128k (GPT-5.3-Codex-Spark).

Direct benchmark comparisons are unavailable — Kimi K1.5 and GPT-5.3-Codex-Spark don't publish scores on any of the same benchmarks.

Frequently asked questions

Kimi K1.5 was released by Moonshot AI on Jan 20 2025.

GPT-5.3-Codex-Spark was released by OpenAI on Feb 12 2026.

Kimi K1.5 has a 128k context window; GPT-5.3-Codex-Spark has 128k.

Other comparisons