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 5.5vsGLM 5.3 Flash
Updated Sep 2026

Claude Opus 5.5vsGLM 5.3 Flash

GLM 5.3 Flash is cheaper than Claude Opus 5.5 at $0.15/M vs $4/M input tokens.

Claude Opus 5.5 and GLM 5.3 Flash compared across 15 shared prompts
SpecClaude Opus 5.5GLM 5.3 Flash
Input price$4/M tokens$0.15/M tokens
Output price$20/M tokens$0.5/M tokens
Context window1.0M tokens1.3M tokens
WeightsClosedOpen
Free API (OpenRouter)NoNo
ReleasedSep 2026Aug 2026
Side by side

Same prompt, both answers

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

Michelin Star Recipe Design

Design an innovative recipe for a multi-component dish worthy of a Michelin 3-star restaurant. The recipe should feature an unusual…

Claude Opus 5.52,253 words
"Hive & Tide" Langoustine, Beeswax, White Chocolate & Oscietra Caviar, Hay-Baked Celeriac, Fermented Green Strawberry, Sea Buckthorn I. The Concept Most coastal menus celebrate the meeting of sea and land. This dish is about a stranger, quieter meeting: the meadow and the seabed, the bee and the langoustine.
Read the full answer
GLM 5.3 Flash720 words
"Ember & Tide" — Charred Banana Peel Consommé with Sea Urchin, Hay-Smoked Foie Gras, and Black Garlic Beurre Blanc Conceptual Narrative This dish explores the dialogue between decay and luxury — ingredients usually discarded (banana peels, hay stalks) elevated alongside opulent ones (uni, foie gras).
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
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…
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
GLM 5.3 Flash1,276 words
The Experienced Software Engineer You know how a load balancer routes requests, how a cache stores frequently-accessed data, how a database index lets you find a needle without scanning the haystack? An LLM is a fundamentally different kind of system: it's a learned lookup, not a designed one.
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
GLM 5.3 Flash205 words
Golden Hour Garlic Butter Pasta A silky, savory pasta that comes together faster than delivery! Ingredients (serves 2): 8 oz spaghetti or any pasta 4 tbsp butter 4 cloves garlic, minced (or 1 tsp garlic powder) ½ cup grated Parmesan cheese ½ cup pasta water (reserved) 1 tsp red pepper flakes Salt Prep time: 5 minutes…
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
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.
Read the full answer

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 5.53,435 words
The Transistor in 1920: A Counterfactual Through 1980 First, a Reality Check on the Premise A transistor "invented" in 1920 would not have changed the world in 1920. The actual 1947 transistor rested on three foundations that did not exist yet: Quantum theory of solids.
Read the full answer
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.
Read the full answer
Our Verdict
Claude Opus 5.5
Claude Opus 5.5
GLM 5.3 Flash
GLM 5.3 Flash

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

GLM 5.3 Flash costs 40x less per token.

Too close to call
API pricing

Cost per 1M tokens

Claude Opus 5.5
Input
$4.00
Output
$20.00
GLM 5.3 Flash
Input
$0.15
27× cheaper
Output
$0.50
40× cheaper

GLM 5.3 Flash is cheaper on both: 27× input, 40× output.

Where to run it

35 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
GLM 5.3 Flash31 hosts
HostInOutContextUptime
IInferenceNetfp4$0.04 in·$0.14 out·1M·99.6% upSSail Researchfp8$0.04 in·$0.60 out·1M·100% upRRelace$0.07 in·$0.28 out·1M·99.9% upOOpenInferencefp4$0.07 in·$0.36 out·1M·99.6% upDDeepInfrafp4$0.07 in·$0.25 out·1M·99.6% upWWafer$0.09 in·$0.35 out·1M·99.8% up
25 more hostsFewer hosts
GGMI Cloudfp8$0.09 in·$0.30 out·1M·99.1% upMMorph$0.10 in·$0.34 out·1M·89% upDDecartfp4$0.13 in·$0.42 out·1M·98.5% upPPhalafp8$0.13 in·$0.42 out·1M·98.9% upNNovitafp8$0.13 in·$0.44 out·1M·99.3% upSStreamLakefp8$0.14 in·$0.47 out·1M·99.3% upIio.netfp8$0.14 in·$0.47 out·262k·98.3% upAAtlasCloudfp8$0.15 in·$0.50 out·1M·99.5% upBBasetenfp8$0.15 in·$0.50 out·1M·99.4% upCCoreWeavenvfp4$0.15 in·$0.50 out·1M·99.6% upCCrusoefp4$0.15 in·$0.50 out·1M·96.6% upDDigitalOcean$0.15 in·$0.50 out·1M·99.5% upFFireworks$0.15 in·$0.50 out·1M·99.4% upFFriendli$0.15 in·$0.50 out·1M·98.8% upIInceptronfp8$0.15 in·$0.50 out·1M·99.5% upModalnvfp4$0.15 in·$0.50 out·1M·99.9% upNNear AIfp8$0.15 in·$0.50 out·1M·99.6% upPParasailfp8$0.15 in·$0.50 out·1M·99.6% upRReka$0.15 in·$0.50 out·262k·99.7% upSSiliconFlowfp8$0.15 in·$0.50 out·1M·99.7% upTTogether$0.15 in·$0.50 out·1M·99.5% upVVenice$0.15 in·$0.50 out·1M·97.7% upZ.aifp8$0.15 in·$0.50 out·1M·99.6% upNNextBitfp8$0.17 in·$0.55 out·1M·99.7% upCloudflare Workers AI$0.30 in·$1.00 out·1.3M·99.8% 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 GLM 5.3 Flash is developed by Zhipu AI. Claude Opus 5.5 has a 1.0M 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.

It depends on your use case. Claude Opus 5.5 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.

Claude Opus 5.5 costs $4/M input tokens and GLM 5.3 Flash costs $0.15/M input tokens. GLM 5.3 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 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.

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
GLM 5.3 Flash logoQwen3.8 Max Prime logo
GLM 5.3 Flash 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
GLM 5.3 Flash logoQwen3.8 Omni Flash logo
GLM 5.3 Flash vs Qwen3.8 Omni FlashLanded Sep 2026
Claude Opus 5.5 logoCommand A+ logo
Claude Opus 5.5 vs Command A+Landed Sep 2026
GLM 5.3 Flash logoGPT-6 Luna Pro logo
GLM 5.3 Flash 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
GLM 5.3 Flash logoGPT-6 Luna logo
GLM 5.3 Flash 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
GLM 5.3 Flash logoGLM 5.3 logo
GLM 5.3 Flash vs GLM 5.3Same lab
GLM 5.3 Flash logoGLM 5.3 FlashX logo
GLM 5.3 Flash vs GLM 5.3 FlashXSame lab
GLM 5.3 Flash logoERNIE 4.5 300B A47B logo
GLM 5.3 Flash vs ERNIE 4.5 300B A47BNew provider
GLM 5.3 Flash logoOpenRouter Fusion · Budget (Jun 2026) logo
GLM 5.3 Flash vs OpenRouter Fusion · Budget (Jun 2026)New provider
GLM 5.3 Flash logoOpenRouter Fusion · Quality (Jun 2026) logo
GLM 5.3 Flash vs OpenRouter Fusion · Quality (Jun 2026)New provider
GLM 5.3 Flash logoGemini 1.5 Pro logo
GLM 5.3 Flash vs Gemini 1.5 ProSame size

Model pages

Claude Opus 5.5 logo
Claude Opus 5.519 outputs, specs and price
GLM 5.3 Flash logo
GLM 5.3 Flash15 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