GPT-5 Medium vs Kimi K2-Thinking-0905: Specs & Benchmark Comparison

CharacteristicGPT-5 MediumKimi K2-Thinking-0905
CompanyOpenAIMoonshot AI
Release DateAugust 6, 2025September 4, 2025
Parameters1.0T
MultimodalYesNo
Context (input)400K262K
Context (output)64K66K
Input Price / 1M$0.75$0.60
Output Price / 1M$3.00$2.40
Average Score0.90.9
Benchmarks
AIME 20250.91.0
GPQA0.90.8

Visual Benchmark Comparison

GPT-5 Medium
Kimi K2-Thinking-0905
AIME 20250.9 vs 1.0
0.9
1.0
GPQA0.9 vs 0.8
0.9
0.8

Verdict

Kimi K2-Thinking-0905 leads in 2 out of 4 comparison categories.

Overall Performance

Both models show comparable average scores: GPT-5 Medium — 0.9, Kimi K2-Thinking-0905 — 0.9.

API Cost

Kimi K2-Thinking-0905 is 1.3x cheaper: input $0.60/1M vs $0.75/1M tokens.

Context Window

GPT-5 Medium supports a larger context: 400K vs 262K tokens.

Recency

Kimi K2-Thinking-0905 is newer: released 9/4/2025 vs 8/6/2025.

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The GPT-5 Medium and Kimi K2-Thinking-0905 comparison is updated for 2026. Data includes benchmark results, API pricing, context window size and other specifications. For more detailed information, visit the GPT-5 Medium or Kimi K2-Thinking-0905 page. See also the complete list of AI model comparisons.