gpt-oss (OpenAI)
Free tier available
- Self-hosted (Free, Apache 2.0)$0
- API (OpenRouter / Together / Fireworks)$0.15/per 1M input tokens (120b tier)
Our pickgpt-oss (OpenAI)

Kimi K3 (Moonshot)
Tier-list head-to-head. gpt-oss (OpenAI) takes the A-tier slot — here's the breakdown.
Spec sheet
| Tier | A-tier | A-tier |
| Overall score | 8.1 / 10 | 8.1 / 10 |
| Free tier | Yes | Yes |
| Starting price | $0 | $3 / $15 |
| Best for | Developers who want OpenAI-brand open-weight reasoning models for self-hosting or fine-tuning. | Agentic coding workflows, tool-use agents, long-horizon repository work (1M context), and teams who want fr… |
| Last reviewed | 2026-04-17 | 2026-09-05 |
Head-to-head
Rated 1-10 on the same rubric across all 130 tools we cover.
What you'll pay
Look past the headline number -- entry-tier limits drive most cost surprises.
Free tier available
Free tier available
Kimi K3 (2.8T, launched 2026-07-16) -- Arena.AI ranked it best-available at launch; vendor claims parity with Fable 5, third-party suites pending. Scores below are K2.6/K2.5-era baselines retained until K3 third-party runs publish benchmarks — gpt-oss (OpenAI) has no published benchmarks
| Benchmark | Description | Score |
|---|---|---|
| SWE-Bench Pro | 58.6% | |
| MMLU-Pro (K2.5 baseline) | 84.8% | |
| GPQA Diamond (K2.5 baseline) | 80.5% | |
| AIME 2025 (K2.5 baseline) | 91.2% | |
| LiveCodeBench (K2.5 baseline) | 74.1% |
The decision
Use-case anchors and category strengths, side by side.
Developers who want OpenAI-brand open-weight reasoning models for self-hosting or fine-tuning. Particularly good for single-GPU deployments (gpt-oss-120b on one 80GB card) or edge-device reasoning (gpt-oss-20b on 16GB consumer GPUs / Apple Silicon). Also good as a reliable baseline when comparing newer open-weight releases.
Visit gpt-oss (OpenAI)Agentic coding workflows, tool-use agents, long-horizon repository work (1M context), and teams who want frontier-tier quality at a fraction of frontier pricing ($15/M output vs Fable 5's $50/M).
Visit Kimi K3 (Moonshot)Bottom line
gpt-oss (OpenAI) (A-tier, 8.1/10) and Kimi K3 (Moonshot) (A-tier, 8.1/10) are within margin-of-error of each other on overall score. There's no decisive winner -- the right pick comes down to how you'll actually use the tool, not which scored higher in the abstract. We rate them on the same rubric (ease of use, output quality, value, features), and on this pair the rubric is calling it a draw.
Pricing-wise, both tools have a free tier (gpt-oss (OpenAI) starts $0, Kimi K3 (Moonshot) starts $3 / $15), so you can test either without committing. Compare what each free tier actually unlocks -- usage caps, model access, and feature gates differ a lot more than the headline price suggests, especially as both vendors have tightened limits in 2026.
By use case: pick gpt-oss (OpenAI) when developers who want openai-brand open-weight reasoning models for self-hosting or fine-tuning. Pick Kimi K3 (Moonshot) when agentic coding workflows, tool-use agents, long-horizon repository work (1m context), and teams who want frontier-tier quality at a fraction of frontier pricing ($15/m output vs fable 5's $50/m). The two tools aren't fighting for the same person -- they're aiming at adjacent jobs that occasionally overlap. If you're squarely in gpt-oss (OpenAI)'s lane, the tier-list ranking and the use-case fit point the same direction; if you're in Kimi K3 (Moonshot)'s lane, the score gap matters less than the fit.
Bottom line: this pair is a coin flip on raw scores. Choose by use-case fit, free-tier availability, and which one you can actually try without committing. Re-evaluate in 60-90 days -- both vendors are shipping fast in 2026.
Keep digging
Full gpt-oss (OpenAI) review
Tier A · 8.1/10
Full Kimi K3 (Moonshot) review
Tier A · 8.1/10
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Built from our daily AI-tool sweep, last touched September 5, 2026. Honest tier-list reviews — no affiliate-link pieces disguised as advice. See the rubric or how we review.