Skip to content
Rival
How it worksPrivacyTerms
Explore all of Rival

Explore

  • Compare Models
  • All Models
  • Image Comparison
  • Audio Comparison
  • Image Generation
  • Best AI For...
  • Arena
  • API Pricing
  • Challenges

Discover

  • SubjectiveBench
  • Default Index
  • Research
  • Research downloads
  • Rival Kits
  • Find your AI taste
  • UI Glow-Up
  • VoiceLock
  • Cost Cutter
  • Agent skills
  • Benchmarks vs Vibes
  • Brief
  • Jailbreak
  • Model Updates
  • Provider Status
  • AI Creators

Connect

  • Methodology
  • Advertise
  • Partnerships
  • Privacy Policy
  • Terms
  • RSS Feed
  1. Home
  2. /
  3. Compare
  4. /
  5. Claude Opus 5.5vsKimi K2.6
Updated Sep 2026

Claude Opus 5.5vsKimi K2.6

Kimi K2.6 is cheaper than Claude Opus 5.5 at $0.95/M vs $4/M input tokens.

Claude Opus 5.5 and Kimi K2.6 compared across 19 shared prompts
SpecClaude Opus 5.5Kimi K2.6
Input price$4/M tokens$0.95/M tokens
Output price$20/M tokens$4/M tokens
Context window1.0M tokens262K tokens
WeightsClosedOpen
Free API (OpenRouter)NoNo
ReleasedSep 2026Apr 2026
Side by side

Same prompt, both answers

Opening lines from 6 of the 19 prompts both answered. Formatting stripped, words untouched.

Debug This Architecture

Here's the architecture for a real-time collaborative document editor (like Google Docs): **System Overview:** - Frontend: React SPA with…

Claude Opus 5.52,280 words
Architecture Review: Real-Time Collaborative Editor The most serious problems cluster in three areas: the sync model (client-clock LWW), cross-server propagation (per-server WebSockets with DB polling), and the CDN/auth layer, which can leak data between users. Issues are grouped by area below.
Read the full answer
Kimi K2.62,081 words
Here is a systematic breakdown of the critical flaws in this architecture, categorized by the type of risk they introduce. The "2-Second Blindness" – Cross-Server Sync via DB Polling Category: Race Condition / Scaling Bottleneck / Failure Mode Problem: Because WebSocket servers do not communicate with one another…
Read the full answer

Simple 7-Ingredient Recipe

Create a simple recipe for a delicious dish (sweet or savory) using only 7 common pantry ingredients. Include a creative name for the dish…

Claude Opus 5.5300 words
Midnight Silk Noodles Creamy, tangy peanut noodles with a gentle kick, ready faster than takeout. Serves: 2 Prep time: 5 minutes Cook time: 10 minutes Total time: 15 minutes The 7 Ingredients 8 oz (225 g) spaghetti (or any long noodle) ¼ cup creamy peanut butter 3 tablespoons soy sauce 1 tablespoon honey (or sugar) 1…
Read the full answer
Kimi K2.6286 words
The Blanket Fort Stew (Rustic One-Pot Pasta e Ceci) A warm, garlicky hug of a meal built from true shelf-stable staples. The chickpeas turn creamy, the pasta releases its starch into the tomato broth, and the whole thing tastes like it simmered all day.
Read the full answer

Mini LBO Underwrite

You are underwriting a 5-year LBO for a private equity investment committee. Company (fictional): HarborTech Services (HTS) –…

Claude Opus 5.5900 words
HarborTech Services: 5-Year LBO Underwriting Conventions: $m. Interest is charged on beginning-of-year balances, which avoids circularity. Term Loan (TL) amortization is 1% of the original $480m, or $4.8m per year. Mezz PIK accrues to principal. All FCF after mandatory debt service sweeps to the TL.
Read the full answer
Kimi K2.6596 words
1. SOURCES & USES (FY2025 CLOSE) $m Purchase Price (12.0 × $120m EBITDA) 1,440.0 Transaction Fees (2.0% of EV) 28.8 Total Uses 1,468.8 Term Loan (4.0×) 480.0 Mezzanine (1.5×) 180.0 Equity 808.8 2. YEAR-BY-YEAR MODEL (FY2026–FY2030) All figures in $m.
Read the full answer

Startup Pitch Teardown

Here's a pitch deck summary for a startup called "MindMeld AI": **Slide 1 - Vision:** "We're building the future of human-AI collaboration.…

Claude Opus 5.5936 words
The 3 Weakest Claims in the MindMeld AI Pitch "Decodes neural patterns into text with 94% accuracy. Works with any language, any device." (Slide 3) Why it's weak: It far exceeds the published state of the art. The best results for thought-to-text come from invasive implants.
Read the full answer
Kimi K2.6701 words
Here are the three weakest claims in the MindMeld AI pitch, ranked by their potential to destroy investor credibility. The "Pre-Cognition" Claim The Claim: "MindMeld AI reads your brainwaves to predict what you want to type before you think it" (Slide 1) Why it is weak: This is neuroscientifically incoherent.
Read the full answer

Ethical Dilemma with Stakeholders

You're the CEO of a pharmaceutical company. Your best-selling drug ($2B annual revenue, used by 4 million patients for chronic pain) has…

Claude Opus 5.51,853 words
The Next 48 Hours: CEO Action Plan The Core Decision We disclose. The question is how to do it well, not whether. Before the schedule, here are the three facts that drive every decision below. 1. The harm is concrete.
Read the full answer
Kimi K2.62,483 words
My north star: We disclose—fast, fully, and on our terms. The “wait for more data” option is a mirage. It exposes the company to criminal liability under FDA adverse-event reporting rules, potential DOJ investigation, securities fraud charges, and derivative litigation that could destroy the firm.
Read the full answer

Explain Like I'm a Specific Expert

Explain how a large language model (like GPT or Claude) learns and generates text to each of these three audiences: 1. **An experienced…

Claude Opus 5.51,442 words
How Large Language Models Work: Three Explanations For the Experienced Software Engineer Think of an LLM as a single, very large pure function: f(tokens[0..n]) → probability distribution over tokens[n+1]. Text is chunked into tokens (roughly word fragments, from a vocabulary of about 100k).
Read the full answer
Kimi K2.6877 words
1. Experienced Software Engineer Think of an LLM not as a program you write, but as a binary you compile from the entire internet. Instead of hand-crafting if/then rules, you define a single objective: given the context "The cat sat on the...", output the probability distribution over every possible next token, and…
Read the full answer
Our Verdict
Claude Opus 5.5
Claude Opus 5.5
Kimi K2.6
Kimi K2.6Runner-up

Not enough votes to call it. On the specs, Claude Opus 5.5 has the edge: newer, bigger context window, major provider backing.

Kimi K2.6 costs 5.0x less per token.

Too close to call

Reviewing agent-written code?See a Brief PR report

API pricing

Cost per 1M tokens

Claude Opus 5.5
Input
$4.00
Output
$20.00
Kimi K2.6
Input
$0.95
4.2× cheaper
Output
$4.00
5.0× cheaper

Kimi K2.6 is cheaper on both: 4.2× input, 5.0× output.

Where to run it

24 hosts, cheapest first

Claude Opus 5.54 hosts
HostInOutContextUptime
Amazon Bedrock$4.00 in·$20.00 out·1M·99.8% upAzure AI Foundry$4.00 in·$20.00 out·1M·100% upAnthropic$4.00 in·$20.00 out·1M·100% upGoogle Vertex AI$4.00 in·$20.00 out·1M·100% up
Kimi K2.620 hosts
HostInOutContextUptime
Baidu Qianfanfp4$0.45 in·$1.90 out·262k·100% upIInceptronint4$0.45 in·$2.97 out·262k·99.5% upCChutesint4$0.50 in·$2.85 out·262k·98.7% upDDecartfp4$0.59 in·$2.47 out·262k·97.7% upSStreamLakefp8$0.60 in·$2.52 out·256k·99.2% upCCoreWeavefp4$0.65 in·$3.41 out·262k·98.8% up
14 more hostsFewer hosts
DDeepInfrafp4$0.75 in·$3.50 out·262k·98.9% upVVeniceint4$0.75 in·$3.50 out·256k·97.5% upSSiliconFlowfp8$0.77 in·$3.40 out·262k·99.8% upNNovita$0.80 in·$3.40 out·262k·99.8% upGGMI Cloudfp8$0.85 in·$3.60 out·262k·99.4% upAAtlasCloudint4$0.95 in·$4.00 out·262k·99.1% upBBasetenfp4$0.95 in·$4.00 out·262k·98.7% upCloudflare Workers AI$0.95 in·$4.00 out·262k·99.9% upMoonshot AIint4$0.95 in·$4.00 out·262k·100% upPPhala$1.09 in·$4.60 out·262k·99.6% upDDigitalOceandegraded$0.57 in·$2.40 out·262k·97.4% upCCrusoebf16degraded$0.70 in·$3.50 out·262k·84% upPParasailint4degraded$0.75 in·$3.50 out·262k·98.7% upFFireworksdegraded$0.95 in·$4.00 out·262k·0% up

Per million tokens. Prices and uptime via OpenRouter, checked 25 Sep 2026.

Research

What we learned reading every model

FAQ

Common questions

Claude Opus 5.5 is developed by Anthropic while Kimi K2.6 is developed by Moonshot AI. Claude Opus 5.5 has a 1.0M token context window vs Kimi K2.6's 262K. You can compare their actual outputs across 19 challenges on Rival to see how they differ in practice.

It depends on your use case. Claude Opus 5.5 and Kimi K2.6 each have strengths in different areas. Rival lets you compare their real outputs side-by-side across 19 challenges so you can judge which fits your needs best.

Claude Opus 5.5 costs $4/M input tokens and Kimi K2.6 costs $0.95/M input tokens. Kimi K2.6 is $3.05/M cheaper per input. Check their side-by-side outputs on Rival to see if the price difference is justified by quality.

This page shows a side-by-side comparison of Claude Opus 5.5 and Kimi K2.6 across shared challenges. You can vote on which model produced the better output in a blind duel. Browsing and voting are free. No account is needed to look; signing in only saves your votes and likes.

Keep exploring

More comparisons

Against the newest arrivals

Claude Opus 5.5 logoSolar Mini 4 logo
Claude Opus 5.5 vs Solar Mini 4Landed Sep 2026
Kimi K2.6 logoQwen3.8 Max Prime logo
Kimi K2.6 vs Qwen3.8 Max PrimeLanded Sep 2026
Claude Opus 5.5 logoGLM 5.3 Prime logo
Claude Opus 5.5 vs GLM 5.3 PrimeLanded Sep 2026
Kimi K2.6 logoQwen3.8 Omni Flash logo
Kimi K2.6 vs Qwen3.8 Omni FlashLanded Sep 2026
Claude Opus 5.5 logoCommand A+ logo
Claude Opus 5.5 vs Command A+Landed Sep 2026
Kimi K2.6 logoGPT-6 Luna Pro logo
Kimi K2.6 vs GPT-6 Luna ProLanded Sep 2026
Claude Opus 5.5 logoGPT-6 Sol Pro logo
Claude Opus 5.5 vs GPT-6 Sol ProLanded Sep 2026
Kimi K2.6 logoGPT-6 Luna logo
Kimi K2.6 vs GPT-6 LunaLanded Sep 2026

Same lab, same size, long tail

Claude Opus 5.5 logoClaude Opus 4.6 logo
Claude Opus 5.5 vs Claude Opus 4.6Same lab
Claude Opus 5.5 logoClaude Fable 5.1 logo
Claude Opus 5.5 vs Claude Fable 5.1Same lab
Kimi K2.6 logoKimi K3 logo
Kimi K2.6 vs Kimi K3Same lab
Kimi K2.6 logoKimi K2.7 Code logo
Kimi K2.6 vs Kimi K2.7 CodeSame lab
Kimi K2.6 logoLlama 4 Maverick logo
Kimi K2.6 vs Llama 4 MaverickNew provider
Kimi K2.6 logoLlama 4 Scout logo
Kimi K2.6 vs Llama 4 ScoutNew provider
Claude Opus 5.5 logoMercury logo
Claude Opus 5.5 vs MercuryNew provider
Kimi K2.6 logoMercury 2 logo
Kimi K2.6 vs Mercury 2New provider

Model pages

Claude Opus 5.5 logo
Claude Opus 5.519 outputs, specs and price
Kimi K2.6 logo
Kimi K2.658 outputs, specs and price
Rival
How it worksPrivacyTerms
Explore all of Rival

Explore

  • Compare Models
  • All Models
  • Image Comparison
  • Audio Comparison
  • Image Generation
  • Best AI For...
  • Arena
  • API Pricing
  • Challenges

Discover

  • SubjectiveBench
  • Default Index
  • Research
  • Research downloads
  • Rival Kits
  • Find your AI taste
  • UI Glow-Up
  • VoiceLock
  • Cost Cutter
  • Agent skills
  • Benchmarks vs Vibes
  • Brief
  • Jailbreak
  • Model Updates
  • Provider Status
  • AI Creators

Connect

  • Methodology
  • Advertise
  • Partnerships
  • Privacy Policy
  • Terms
  • RSS Feed