GPT-5.5 vs Kimi K2.6

OpenAI's flagship against Moonshot AI's open-weight coding model — published pricing, context windows and specs, side by side.

Compiled by AI Model Hub · Last updated 8 July 2026 · All figures from the two models' AI Model Hub pages (vendor release materials and independent trackers)

At a glance: GPT-5.5 lists at $5 / $30 per 1M tokens (Thinking) with a 1,000,000 tokens context window; Kimi K2.6 lists at $0.60 / $2.50 per 1M tokens (official) with 262,144 tokens of context. The full spec table, price table and each model's published benchmarks are below.

On this page

Side-by-side specs
Price comparison
What the table says
FAQ

GPT-5.5 vs Kimi K2.6: side-by-side

	GPT-5.5	Kimi K2.6
Maker	OpenAI	Moonshot AI
Released	23 April 2026	20 April 2026
Tier	Flagship	Open-weight coding model
Context window	1,000,000 tokens (400K in Codex CLI)	262,144 tokens
Max output	Not specified	262,142 tokens
API price (per 1M)	$5 / $30 per 1M tokens (Thinking)	$0.60 / $2.50 per 1M tokens (official)
Access	Proprietary — ChatGPT & Codex (Plus, Pro, Business, Enterprise) + API	Open weights — Modified MIT licence (MoE, 1T total params / 32B active)
Best at	Agentic coding, computer use, deep research	Long-horizon coding, multi-agent orchestration
Standout	First full retrain since GPT-4.5 — unified multimodal (text, images, audio, video)	Text, images and video in one architecture; Multi-head Latent Attention

Price comparison

Model	Input (per 1M)	Output (per 1M)
GPT-5.5 (Thinking)	$5.00	$30.00
GPT-5.5 Pro	$30.00	$180.00
Kimi K2.6	$0.60	$2.50

Estimate your monthly API cost for GPT-5.5 vs Kimi K2.6 with the LLM API pricing calculator →

Published benchmark figures

Each figure below is the model's own published score as listed on its AI Model Hub page. Different suites (and suite versions) are not directly comparable.

Model	Benchmark	Published score
GPT-5.5	Terminal-Bench 2.0	82.7%
GPT-5.5	GDPval	84.9%
GPT-5.5	Expert-SWE	73.1%
GPT-5.5	SWE-bench Pro	58.6%
GPT-5.5	FrontierMath Tier 4	35.4%
Kimi K2.6	SWE-bench Pro	58.6%
Kimi K2.6	Humanity's Last Exam (with tools)	54.0%

What the table says

Pricing. GPT-5.5 lists at $5 / $30 per 1M tokens (Thinking); Kimi K2.6 lists at $0.60 / $2.50 per 1M tokens (official). On these published rates, Kimi K2.6's input price is 8.3x lower than GPT-5.5's, and Kimi K2.6's output price is 12x lower than GPT-5.5's. GPT-5.5 Pro lists at $30 / $180 per 1M tokens.
Context. GPT-5.5's context window (1,000,000 tokens (400K in Codex CLI)) is about 3.8x the size of Kimi K2.6's (262,144 tokens).
Access. Kimi K2.6 publishes open weights (Modified MIT licence), so it can be self-hosted; GPT-5.5 is proprietary and available only through hosted APIs and apps.
Benchmarks. On SWE-bench Pro the two models report an identical 58.6%.

Key takeaway

Everything above is drawn from the two models' published rate cards and spec sheets. Which one fits depends on the workload you price it against — run your own token volumes through the pricing calculator to see the monthly difference.

Full GPT-5.5 overview Full Kimi K2.6 overview

Frequently asked questions

Which is cheaper, GPT-5.5 or Kimi K2.6?

Kimi K2.6 — it lists at $0.60 / $2.50 per 1M tokens (official) versus $5 / $30 per 1M tokens (Thinking) for GPT-5.5.

Which has the bigger context window, GPT-5.5 or Kimi K2.6?

GPT-5.5 — 1,000,000 tokens (400K in Codex CLI), versus 262,144 tokens for Kimi K2.6.

Which model is newer?

GPT-5.5 is the more recent release (23 April 2026); Kimi K2.6 was released 20 April 2026.

Can I run GPT-5.5 or Kimi K2.6 locally?

Only Kimi K2.6 — it publishes open weights under the Modified MIT licence. GPT-5.5 is proprietary and only available via hosted APIs and apps.

Related comparisons

Sources & further reading: