Comparisons
Kimi K3.1 Pro vs GPT-6 Astra: The 'One-Fifth the Price' Claim, Checked
The claim traveled fast over the weekend: Moonshot AI's new Kimi K3.1 Pro matches flagship intelligence at "one-fifth the price of GPT-6 Astra." I checked the math against live pricing, and this time the marketing number survives contact with reality — with one caveat most Chinese-language coverage skips: against Moonshot's own July model, K3.1 Pro is actually a price increase.
Verdict: The 1/5 claim is real, at least on OpenRouter's published rates — K3.1 Pro costs $2.00 per million input tokens and $10.00 per million output, against Astra's $10.00/$50.00. That's exactly 1/5 on both sides. If you're paying Astra rates for agent workloads that don't depend on the OpenAI toolchain, K3.1 Pro is worth benchmarking this week. But read the pricing trend correctly: Moonshot raised its input price roughly 8x versus K3 in July. The "cheaper than OpenAI" story is true; the "cheap" story, compared to what Kimi used to cost, is not.
What launched
Moonshot AI announced Kimi K3.1 Pro in the early hours of October 24 Beijing time — a ~3-trillion-parameter open-weights model with a 1M-token context window, positioned as the successor to July's Kimi K3, which was the first 3T-class open model. The company's tech blog followed on October 25 with the "advancing open intelligence" framing. On OpenRouter, moonshotai/kimi-k3.1-pro went live on October 23, and English-language coverage appeared within a day (Unite AI, MindStudio, Eigent), so this is no longer an exclusive window — what's still scarce is a straight pricing audit, which is what this piece is.
The price claim, checked
Side by side, per million tokens (standard tiers):
- GPT-6 Astra: $10.00 input / $1.00 cached input / $50.00 output — OpenAI's own developer pricing page and OpenRouter agree.
- Kimi K3.1 Pro: $2.00 input / $10.00 output — OpenRouter listing, live since October 23.
Both ratios land on 0.2 exactly. The "one-fifth" line is arithmetic, not spin — at least at these two price points. Two honest caveats: OpenRouter's rates can drift from first-party list prices, and benchmark parity is a separate question from price parity; third-party write-ups are already asking whether K3.1 Pro really beats Astra, and I'd treat "approaches flagship" as the vendor's framing until you run your own workload.
The part the weekend clips didn't mention: Kimi got more expensive
The more interesting number is the one against Moonshot's own history. Kimi K3, released July 16, listed on OpenRouter at roughly $0.24 input / $10.80 output. K3.1 Pro's input price of $2.00 is about 8x higher, with output essentially flat. That tracks a pattern we've watched all year: Chinese labs spent the spring undercutting everyone, then — once benchmark credibility was established — started reclaiming pricing power (GLM did the same to overseas API rates in February). The one-fifth discount is real, but it's a discount against Astra, not against Kimi's past self.
Should you switch?
For coding-agent and agentic search workloads, the decision is less about price and more about lock-in: if your stack rides on OpenAI's toolchain (responses API, server-side tools), Astra's premiums buy you integration, and a mid-cycle migration costs more than the token savings. If you're on OpenRouter or a multi-provider setup already — or you self-host open weights — K3.1 Pro at 1/5 rate is the obvious A/B test. On the open-weights side, one honesty note: Moonshot's GitHub organization shows no standalone K3.1 Pro repository as of October 26 (the newest repo remains Kimi-K3 from July, with ~9,000 stars); weights distribution runs through Hugging Face per the company's announcement, though I couldn't pull the HF repo directly from my network to verify file listings — treat the open-weights claim as official-sourced but not independently file-checked by us.
For a counterpoint on what "cheap" means at the API layer, our cheapest DeepSeek API provider comparison covers the same discount logic from DeepSeek's side, and the GLM 5.3 Flash vs DeepSeek V4.1 Flash breakdown shows how fast the mid-tier is consolidating around flash-class models.
Dated caveat: verified October 26, 2026. Prices pulled live from OpenRouter's model API (Kimi K3.1 Pro and K3) and cross-checked against OpenAI's official developer pricing page for GPT-6 Astra (three independent sources agree on $10/$50). Launch date and model specs (3T parameters, 1M context) are from Moonshot's announcement as reported by Beijing Daily — the official announcement text was not directly reviewed. HF weight files not independently verified due to network restrictions on our end; GitHub org state (no standalone K3.1 Pro repo) checked live October 26.