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  5. Claude Opus 5.5vsQwen3.8 Flash
Updated Sep 2026

Claude Opus 5.5vsQwen3.8 Flash

Qwen3.8 Flash is cheaper than Claude Opus 5.5 at $0.15/M vs $4/M input tokens.

Claude Opus 5.5 and Qwen3.8 Flash compared across 10 shared prompts
SpecClaude Opus 5.5Qwen3.8 Flash
Input price$4/M tokens$0.15/M tokens
Output price$20/M tokens$0.47/M tokens
Context window1.0M tokens1.0M tokens
WeightsClosedClosed
Free API (OpenRouter)NoNo
ReleasedSep 2026Aug 2026
Side by side

Same prompt, both answers

Opening lines from 5 of the 10 prompts both answered. Formatting stripped, words untouched.

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
Qwen3.8 Flash1,901 words
The three weakest claims are the ones that most likely trigger investor due-diligence skepticism: technical overclaiming, metric ambiguity, and inconsistent market math. “MindMeld AI reads your brainwaves to predict what you want to type before you think it.”
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
Qwen3.8 Flash147 words
Moon Halo Cookies A soft, golden sugar cookie with crisp edges and a tender center—made with just 7 pantry staples. Prep time: 10 minutes Cook time: 10 minutes Total time: 20 minutes Makes: About 16 cookies Ingredients 1/2 cup butter, softened 3/4 cup sugar 1 egg 1 teaspoon vanilla extract 1 1/2 cups all-purpose flour…
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
Qwen3.8 Flash3,570 words
Assuming this is a U.S.-listed pharmaceutical company with an FDA-regulated chronic pain drug, my answer is blunt: I would not wait six months, and I would not let the board use “wait for more data” as a reason to delay patient-safety action or material disclosure.
Read the full answer

Beginner's Longevity Plan

Outline a simple, actionable 1-month plan for someone starting their journey towards better health and longevity. Focus on 3 key areas…

Claude Opus 5.5653 words
Your 1-Month Starter Plan for Better Health & Longevity The philosophy: Small, consistent changes beat dramatic overhauls. Each week builds on the last, so by Day 30 you'll have a foundation of habits instead of a burned-out resolution.
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Qwen3.8 Flash368 words
1-Month Beginner Health & Longevity Plan Focus areas: Nutrition, Movement, Sleep Week 1: Build the basics Nutrition Add 1 serving of vegetables to 2 meals per day. Drink water with each meal. Choose protein at most meals: eggs, beans, tofu, chicken, fish, yogurt. Movement Walk 10–15 minutes daily.
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
Qwen3.8 Flash983 words
For an experienced software engineer Training a large language model is not “just” making it guess the next word in isolation. It is fitting an enormous parameterized function to predict the next token conditioned on all previous tokens in a sequence.
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Our Verdict
Claude Opus 5.5
Claude Opus 5.5
Qwen3.8 Flash
Qwen3.8 Flash

Not enough votes to call it. On the specs, nothing separates them.

Qwen3.8 Flash costs 43x less per token.

Too close to call
API pricing

Cost per 1M tokens

Claude Opus 5.5
Input
$4.00
Output
$20.00
Qwen3.8 Flash
Input
$0.15
27× cheaper
Output
$0.47
43× cheaper

Qwen3.8 Flash is cheaper on both: 27× input, 43× output.

Where to run it

5 hosts

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
Qwen3.8 Flash1 host
HostInOutContextUptime
Alibaba Cloud$0.15 in·$0.47 out·1M·100% 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 Qwen3.8 Flash is developed by Qwen. Claude Opus 5.5 has a 1.0M token context window vs Qwen3.8 Flash's 1.0M. You can compare their actual outputs across 10 challenges on Rival to see how they differ in practice.

It depends on your use case. Claude Opus 5.5 and Qwen3.8 Flash each have strengths in different areas. Rival lets you compare their real outputs side-by-side across 10 challenges so you can judge which fits your needs best.

Claude Opus 5.5 costs $4/M input tokens and Qwen3.8 Flash costs $0.15/M input tokens. Qwen3.8 Flash is $3.85/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 Qwen3.8 Flash 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.

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Model pages

Claude Opus 5.5 logo
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