GPT-6 Astra vs Kimi K3

Select two models to compare their coding performance, pricing, and features.

Key Takeaways

Coding tier: Kimi K3 has a higher reference index on the selected shared benchmark configuration than GPT-6 Astra (113.02 vs 112.28, a 0.74-point difference). This does not by itself establish general coding superiority. Editorial tiers: GPT-6 Astra = S; Kimi K3 = S. Tiers are separate editorial assessments and do not establish a reliable order within a tier.
API cost estimate: Estimated 1M in / 200K out tokens: $20.0000 (GPT-6 Astra) vs $2.8000 (Kimi K3).
Metric GPT-6 Astra Kimi K3
Coding Index
112.28
113.02
Coding tier S S
Input Price $10/1M $0.8/1M
Output Price $50/1M $10/1M
Context Window 1.05M 1.05M

Coding Index

Coding Index · Reference baseline: 100

GPT-6 Astra 112.28
Kimi K3 113.02

Integer index difference: 0.74

DeepSeek V4 Flash 0731 = 100. The index reflects two shared tests, not capability multiples or statistically established gaps.

Verdict

Both models share an editorial tier. The evidence does not establish a reliable order within it; compare them on your own projects.

Capabilities & Use Cases Comparison

GPT-6 Astra Tier S

Best For
  • •Software engineering
  • •Research
Strengths
  • •Long-horizon software engineering
  • •Advanced analysis and document creation

Kimi K3 Tier S

Best For
  • •Complex reasoning and architecture
  • •Multi-language code generation
  • •Long-horizon agentic tasks
  • •Self-hosting (open weights)
Strengths
  • •Highest-ranked open-weight coding model
  • •Top-tier code generation and architecture skills
  • •Strong long-horizon agentic workflow capability
  • •Excellent DesignArena leader (3D, webapps, codecategories)

GPT-6 Astra

OpenRouter quote 2026-10-11
Benchmark evidence and ranking method · GPT-6 Astra

Cross-checked

Terminal-Bench 4.0 · Codex · max: 58.18% · 95% CI ± 2.79%

Artificial Analysis · GPT-6 Astra (max)

Test configuration: max

Terminal-Bench 2.1: 88.39% · SciCode: 56.48%

LiveBench · 2026-06-25 · gpt-6-astra-max

Coding: 80.36% · Agentic Coding: 57.32%

ModelRank assigns editorial tiers using public coding evidence, not automatic index thresholds or statistically proven classes. Price, speed, context size and sponsorship do not affect tiers.

DeepSeek V4 Flash 0731 = 100. The index reflects two shared tests, not capability multiples or statistically established gaps.

Results reflect particular model configurations. Agent harnesses, reasoning effort, tools, budgets and tasks may differ. Close indices do not establish superiority. B describes a relative position in this selected group, not an inability to code.

Data checked: 2026-09-10. Snapshot date is the retrieval date, not necessarily the evaluation date.

Kimi K3

OpenRouter quote 2026-10-11
Benchmark evidence and ranking method · Kimi K3

Cross-checked

Artificial Analysis · Kimi K3 (max)

Test configuration: max

Terminal-Bench 2.1: 85.02% · SciCode: 59.49%

LiveBench · 2026-06-25 · kimi-k3

Coding: 81.45% · Agentic Coding: 62.17%

ModelRank assigns editorial tiers using public coding evidence, not automatic index thresholds or statistically proven classes. Price, speed, context size and sponsorship do not affect tiers.

DeepSeek V4 Flash 0731 = 100. The index reflects two shared tests, not capability multiples or statistically established gaps.

Results reflect particular model configurations. Agent harnesses, reasoning effort, tools, budgets and tasks may differ. Close indices do not establish superiority. B describes a relative position in this selected group, not an inability to code.

Data checked: 2026-09-10. Snapshot date is the retrieval date, not necessarily the evaluation date.

Results reflect particular model configurations. Agent harnesses, reasoning effort, tools, budgets and tasks may differ. Close indices do not establish superiority. B describes a relative position in this selected group, not an inability to code.

API cost estimate

1M input + 200K output (USD):

GPT-6 Astra: $20.0000

Kimi K3: $2.8000

Estimates use the displayed channel and time band; DeepSeek uses peak rates. Cache discounts, tool fees, long-context price tiers and uncounted additional tokens are excluded.

Frequently Asked Questions

Which model is better for coding: GPT-6 Astra or Kimi K3?

Kimi K3 has a higher reference index on the selected shared benchmark configuration than GPT-6 Astra (113.02 vs 112.28, a 0.74-point difference). This does not by itself establish general coding superiority. Editorial tiers: GPT-6 Astra = S; Kimi K3 = S. Tiers are separate editorial assessments and do not establish a reliable order within a tier.

How do GPT-6 Astra and Kimi K3 compare in API pricing and costs?

GPT-6 Astra: $10/1M input, $50/1M output (OpenRouter quote); Kimi K3: $0.8/1M input, $10/1M output (OpenRouter quote). 1M input + 200K output (USD): $20.0000 vs $2.8000.

What are the context window sizes of GPT-6 Astra and Kimi K3?

GPT-6 Astra provides a 1,050,000 token context window, while Kimi K3 provides 1,048,576 tokens.

Compare current models

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Try GPT-6 Astra → Try Kimi K3 →