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GPT-5.6 Terra vs Kimi K2.8 Preview

Comparing GPT-5.6 Terra and Kimi K2.8 Preview across benchmarks, pricing, and capabilities.

OpenAI · Moonshot AI · Updated for 2026

Which is better?

GPT-5.6 Terra and Kimi K2.8 Preview trade strengths across price, capabilities, and technical limits. The better choice depends on the workload.

GPT-5.6 Terra also accepts a larger context window (1,050,000 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-5.6 Terra

  • you process long inputs — it offers a 1,050,000 token context window

Choose Kimi K2.8 Preview

  • you want the most recent training data — it shipped Sep 2026

At a glance

The differences that matter most.

Benchmark wins
Input price
$2.00 / M
— / M
Output price
$12.00 / M
— / M
Context window
1,050,000
1,048,576

Individual benchmarks

45 reported for GPT-5.6 Terra · 0 for Kimi K2.8 Preview

No common benchmarks found

GPT-5.6 Terra and Kimi K2.8 Previewdon't have any common benchmark datasets to compare. They may have been evaluated on different testing suites.

Human preference

Blind head-to-head votes and playground preference scores

Context Window

Maximum input and output token capacity

GPT-5.6 Terra accepts 1,050,000 input tokens compared to Kimi K2.8 Preview's 1,048,576 tokens. Only GPT-5.6 Terra specifies output context (128,000 tokens).

OpenAI
GPT-5.6 Terra
Input1,050,000 tokens
Output128,000 tokens
Moonshot AI
Kimi K2.8 Preview
Input1,048,576 tokens
Output- tokens
Mon Sep 14 2026 • llm-stats.com

Input capabilities

Documented input modalities across available providers

Both GPT-5.6 Terra and Kimi K2.8 Preview support multimodal inputs.

They are both capable of processing various types of data, offering versatility in application.

GPT-5.6 Terra

Text
Images
Audio
Video

Kimi K2.8 Preview

Text
Images
Audio
Video

License

Usage and distribution terms

Both models are licensed under proprietary licenses.

Both models have usage restrictions defined by their respective organizations.

GPT-5.6 Terra

Proprietary

Closed source

Kimi K2.8 Preview

Proprietary

Closed source

Release Timeline

When each model was launched

GPT-5.6 Terra was released on 2026-07-09, while Kimi K2.8 Preview was released on 2026-09-11.

Kimi K2.8 Preview is 2 months newer than GPT-5.6 Terra.

GPT-5.6 Terra

Jul 9, 2026

2 months ago

Kimi K2.8 Preview

Sep 11, 2026

3 days ago

2mo newer

Knowledge Cutoff

When training data ends

GPT-5.6 Terra has a documented knowledge cutoff of 2026-02-16, while Kimi K2.8 Preview's cutoff date is not specified.

We can confirm GPT-5.6 Terra's training data extends to 2026-02-16, but cannot make a direct comparison without Kimi K2.8 Preview's cutoff date.

GPT-5.6 Terra

Feb 2026

Kimi K2.8 Preview

Provider Availability

GPT-5.6 Terra is available from OpenAI. Kimi K2.8 Preview is available from Moonshot AI.

GPT-5.6 Terra

openai logo
OpenAI
Input Price:Input: $2.00/1MOutput Price:Output: $12.00/1M

Kimi K2.8 Preview

moonshot logo
Unknown Organization
* Prices shown are per million tokens

Outputs Comparison

Notice missing or incorrect data?Start an Issue discussion

Judge for yourself.

Run your own prompts against GPT-5.6 Terra and Kimi K2.8 Preview side-by-side, then vote on the output you prefer.

GPT-5.6 Terra
✓ Preferred
Kimi K2.8 Preview
Open in Playground

FAQ

Common questions about GPT-5.6 Terra vs Kimi K2.8 Preview.

Which is better, GPT-5.6 Terra or Kimi K2.8 Preview?

GPT-5.6 Terra (OpenAI) and Kimi K2.8 Preview (Moonshot AI) each have strengths in different areas. Compare their benchmark scores, pricing, context windows, and capabilities above to determine which fits your needs.

How does GPT-5.6 Terra compare to Kimi K2.8 Preview in benchmarks?

GPT-5.6 Terra scores Connectors: 100.0%, HealthBench Consensus: 95.1%, Search and Function-Calling: 94.6%, GPQA: 92.9%, Capture-the-Flag Challenges (Internal): 91.8%.

What are the context window sizes for GPT-5.6 Terra and Kimi K2.8 Preview?

GPT-5.6 Terra supports 1.1M tokens and Kimi K2.8 Preview supports 1.0M tokens. A larger context window lets you process longer documents, conversations, or codebases in a single request.

What are the main differences between GPT-5.6 Terra and Kimi K2.8 Preview?

Key differences include context window (1.1M vs 1.0M). See the full comparison above for benchmark-by-benchmark results.

Who makes GPT-5.6 Terra and Kimi K2.8 Preview?

GPT-5.6 Terra is developed by OpenAI and Kimi K2.8 Preview is developed by Moonshot AI.