What is the difference between Claude Opus 4.1 and GLM 5.3 Flash?

Claude Opus 4.1 is developed by Anthropic while GLM 5.3 Flash is developed by Zhipu AI. Claude Opus 4.1 has a 200K token context window vs GLM 5.3 Flash's 1.3M. You can compare their actual outputs across 15 challenges on Rival to see how they differ in practice.

Which is better, Claude Opus 4.1 or GLM 5.3 Flash?

It depends on your use case. Claude Opus 4.1 and GLM 5.3 Flash each have strengths in different areas. Rival lets you compare their real outputs side-by-side across 15 challenges so you can judge which fits your needs best.

How much does Claude Opus 4.1 cost compared to GLM 5.3 Flash?

Claude Opus 4.1 costs $15/M input tokens and GLM 5.3 Flash costs $0.15/M input tokens. GLM 5.3 Flash is $14.85/M cheaper per input. Check their side-by-side outputs on Rival to see if the price difference is justified by quality.

How can I compare Claude Opus 4.1 and GLM 5.3 Flash on Rival?

This page shows a side-by-side comparison of Claude Opus 4.1 and GLM 5.3 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.

Updated Aug 2026

Claude Opus 4.1vsGLM 5.3 Flash

GLM 5.3 Flash is cheaper than Claude Opus 4.1 at $0.15/M vs $15/M input tokens.

Claude Opus 4.1 and GLM 5.3 Flash compared across 15 shared prompts
Spec	Claude Opus 4.1	GLM 5.3 Flash
Input price	$15/M tokens	$0.15/M tokens
Output price	$75/M tokens	$0.5/M tokens
Context window	200K tokens	1.3M tokens
Weights	Closed	Open
Free API (OpenRouter)	No	No
Released	Aug 2025	Aug 2026

Side by side

Same prompt, both answers

Opening lines from 6 of the 15 prompts both answered. Formatting stripped, words untouched.

Historical Counterfactual Analysis

If the transistor had been invented in 1920 instead of 1947, trace the likely technological, economic, and geopolitical implications through…

Claude Opus 4.11,201 words

The Transistor Timeline Shift: A Cascade of Consequences The 1920s-1930s: The Foundation Disruption Immediate Technical Revolution With the transistor arriving in 1920, likely from Bell Labs or a European research institution, the first decade would see rapid miniaturization of radio equipment.

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GLM 5.3 Flash1,314 words

Counterfactual: The Transistor in 1920 Preliminary Framing A 1920 transistor presumes vacuum-tube-era physics knowledge outpacing reality—quantum mechanics wasn't mature until 1926–28, so a working device would likely be an empirical oddity (like the actual point-contact transistor) imperfectly understood.

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Mini LBO Underwrite

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

Claude Opus 4.1364 words

SIMPLIFIED LBO MODEL Entry Calculations Enterprise Value: 12.0x × $120m = $1,440m Transaction Fees: 2.0% × $1,440m = $28.8m Term Loan: 4.0x × $120m = $480m Mezzanine: 1.5x × $120m = $180m Total Debt: $660m Equity Investment: $1,440m - $660m + $28.8m = $808.8m Year-by-Year Projections (FY2026-FY2030) $ millions FY2026…

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GLM 5.3 Flash518 words

HarborTech Services — 5-Year LBO Summary Entry Math EV = 12.0x × $120m = $1,440.0m; Fees (2%) = $28.8m; Total uses = $1,468.8m Debt: TL = 4.0x × 120 = $480.0m; Mezz = 1.5x × 120 = $180.0m; Total = $660.0m (5.5x) Sponsor equity = $808.8m Base Case Projection ($m) FY26 FY27 FY28 FY29 FY30 Revenue 972.0 1,039.7 1,102.1…

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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 4.1875 words

48-Hour Crisis Action Plan Immediate Decision Framework Core Principle: Patient safety supersedes all other considerations. Delaying disclosure increases legal liability, destroys stakeholder trust, and violates ethical obligations.

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GLM 5.3 Flash1,321 words

48-Hour Action Plan: Liver Failure Signal in Flagship Drug Guiding Principle First The side effect is real, the drug is in 4 million patients, and roughly 500 patients per year may develop liver failure (4M ÷ 8,000). Every day of delay is measured in preventable liver transplants and deaths.

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Advanced Longevity Plan (Biohacker)

Develop a comprehensive, cutting-edge 3-month longevity plan for a biohacker aiming to optimize longevity, physical and cognitive…

Claude Opus 4.11,265 words

Advanced 3-Month Biohacker Longevity Optimization Protocol Overview & Philosophy This protocol integrates evidence-based interventions targeting the nine hallmarks of aging while optimizing immediate performance metrics.

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GLM 5.3 Flash1,294 words

90-Day Longevity Optimization Protocol ⚠️ Medical disclaimer: This is an educational framework, not medical advice. Before starting, complete baseline labs and consult a physician—especially before fasting, supplements (rapamycin off-label use, high-dose anything), or if you have any health conditions.

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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 4.1414 words

Your 1-Month Health & Longevity Kickstart Plan Week 1-2: Foundation Building Start small and build consistency with these three pillars: 🥗 NUTRITION: Simple Whole Foods Week 1: Add one serving of vegetables to lunch and dinner (frozen veggies count!)

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GLM 5.3 Flash327 words

1-Month Beginner Health & Longevity Plan 🥗 Area 1: Diet — "Add Before You Subtract" Week 1: Add one vegetable or fruit to every meal. Don't cut anything yet—just add. Week 2: Swap one sugary drink per day for water or unsweetened tea.

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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 4.1538 words

Critical Issues Analysis Split-Brain Real-time Synchronization Problem: Users connected to different API servers experience 2+ second delays due to polling mechanism, creating divergent document states and poor collaboration experience.

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GLM 5.3 Flash1,516 words

Architecture Review: Collaborative Document Editor This architecture has several critical flaws that would break the core product promise (real-time collaboration). Let me work through them by severity.

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Our Verdict

Claude Opus 4.1

GLM 5.3 Flash

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

GLM 5.3 Flash costs 150x less per token.

Too close to call

API pricing

Cost per 1M tokens

Claude Opus 4.1

Input

$15.00

Output

$75.00

GLM 5.3 Flash

Input

$0.15

100× cheaper

Output

$0.50

150× cheaper

GLM 5.3 Flash is cheaper on both: 100× input, 150× output.

Where to run it

31 hosts, cheapest first

Claude Opus 4.11 host

HostInOutContextUptime

Amazon Bedrock$15.00 in$75.00 out200k100% up

GLM 5.3 Flash30 hosts

HostInOutContextUptime

DeepInfrafp4$0.07 in$0.25 out1M99.1% up GMI Cloudfp8$0.07 in$0.25 out1M99.2% up Morph$0.08 in$0.28 out1M100% up InferenceNetfp4$0.09 in$0.28 out1M97.5% up Wafer$0.10 in$0.35 out1M99.7% up OpenInferencefp4$0.10 in$0.50 out1M98.6% up

24 more hosts

Relace$0.11 in$0.36 out1M99.7% up Phalafp8$0.13 in$0.42 out1M99.5% up Novitafp8$0.13 in$0.44 out1M99.4% up StreamLakefp8$0.14 in$0.47 out1M99% up Sail Researchfp8$0.14 in$0.47 out1M99% up AtlasCloudfp8$0.15 in$0.50 out1M99.6% up Basetenfp8$0.15 in$0.50 out1M98.7% up CoreWeavenvfp4$0.15 in$0.50 out1M99.5% up DigitalOcean$0.15 in$0.50 out1M93.7% up Fireworks$0.15 in$0.50 out1M99% up Friendli$0.15 in$0.50 out1M98.7% up Inceptronfp8$0.15 in$0.50 out1M98.2% up io.netfp8$0.15 in$0.50 out262k99.2% up Near AIfp8$0.15 in$0.50 out1M98.9% up Parasailfp8$0.15 in$0.50 out1M98.7% up Rekafp8$0.15 in$0.50 out262k98.9% up SiliconFlowfp8$0.15 in$0.50 out1M99.7% up Together$0.15 in$0.50 out1M99.5% up Venice$0.15 in$0.50 out1M98.8% up Z.aifp8$0.15 in$0.50 out1M96.5% up NextBitfp8$0.18 in$0.60 out1M97.9% up Cloudflare Workers AI$0.30 in$1.00 out1.3M99.8% up Modalfp8$0.45 in$1.50 out1M99.6% up Crusoefp4degraded$0.15 in$0.50 out1M93% up

Per million tokens. Prices and uptime via OpenRouter, checked 22 Sep 2026.

Research

What we learned reading every model

FAQ

Common questions

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More comparisons

Same prompt, both answers

Cost per 1M tokens

31 hosts, cheapest first

What we learned reading every model

Common questions

What is the difference between Claude Opus 4.1 and GLM 5.3 Flash?

Which is better, Claude Opus 4.1 or GLM 5.3 Flash?

How much does Claude Opus 4.1 cost compared to GLM 5.3 Flash?

How can I compare Claude Opus 4.1 and GLM 5.3 Flash on Rival?

More comparisons

Against the newest arrivals

Same lab, same size, long tail

Model pages

Same prompt, both answers

Cost per 1M tokens

31 hosts, cheapest first

What we learned reading every model

Common questions

What is the difference between Claude Opus 4.1 and GLM 5.3 Flash?

Which is better, Claude Opus 4.1 or GLM 5.3 Flash?

How much does Claude Opus 4.1 cost compared to GLM 5.3 Flash?

How can I compare Claude Opus 4.1 and GLM 5.3 Flash on Rival?

More comparisons

Against the newest arrivals

Same lab, same size, long tail

Model pages