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 5.5vsGPT-5.3 Chat
Updated Sep 2026

Claude Opus 5.5vsGPT-5.3 Chat

GPT-5.3 Chat is cheaper than Claude Opus 5.5 at $1.75/M vs $4/M input tokens.

Claude Opus 5.5 and GPT-5.3 Chat compared across 19 shared prompts
SpecClaude Opus 5.5GPT-5.3 Chat
Input price$4/M tokens$1.75/M tokens
Output price$20/M tokens$14/M tokens
Context window1.0M tokens128K tokens
WeightsClosed—
Free API (OpenRouter)NoNo
ReleasedSep 2026Mar 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
GPT-5.3 Chat782 words
Key issues fall into consistency, real‑time propagation, storage, scaling, and security. WebSocket broadcast only reaches clients on the same server Problem: Each server only broadcasts to its own connections. Clients connected to other servers only see updates after the 2‑second polling delay.
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
GPT-5.3 Chat395 words
Claim: “Reads your brainwaves to predict what you want to type before you think it.” Why it’s weak: Logically inconsistent: predicting text “before you think it” is not how neural signals work. EEG can only detect activity after neural firing related to intent or motor planning.
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
GPT-5.3 Chat844 words
All figures in $ millions unless noted. ENTRY (end FY2025) EBITDA = 120 Enterprise value = 12.0 × 120 = 1,440 Transaction fees = 2% × 1,440 = 28.8 Debt at close Term Loan = 4.0 × 120 = 480 Mezzanine = 1.5 × 120 = 180 Equity = EV − Debt + fees = 1,440 − 660 + 28.8 = 808.8 Starting balances Term Loan = 480 Mezz = 180…
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
GPT-5.3 Chat718 words
0–2 hours • Verify the signal immediately. Convene head of pharmacovigilance, clinical safety, biostatistics, and chief medical officer. Require raw data, case narratives, statistical analysis, and comparison to baseline liver‑failure incidence.
Read the full answer

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
GPT-5.3 Chat785 words
Dish name: “Forest & Tide: Scallop, Aged Soy, Pine, and Dark Chocolate” Concept narrative This dish explores the meeting point of ocean depth and forest aromatics. Sweet raw scallop is paired with an unexpected partner: extremely light dark chocolate bitterness and pine brightness.
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.
Read the full answer
GPT-5.3 Chat361 words
Goal: build a few simple habits you can sustain. Focus areas: diet, movement, sleep. Keep it easy and consistent. Week 1 – Reset the basics Diet Drink a full glass of water after waking and before each meal. Add one fruit or vegetable to every meal. Reduce sugary drinks; replace with water or unsweetened tea.
Read the full answer
Our Verdict
Claude Opus 5.5
Claude Opus 5.5
GPT-5.3 Chat
GPT-5.3 ChatRunner-up

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

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
GPT-5.3 Chat
Input
$1.75
2.3× cheaper
Output
$14.00
1.4× cheaper

GPT-5.3 Chat is cheaper on both: 2.3× input, 1.4× output.

Where to run it

4 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
GPT-5.3 Chat

No hosts listed on OpenRouter.

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 GPT-5.3 Chat is developed by OpenAI. Claude Opus 5.5 has a 1.0M token context window vs GPT-5.3 Chat's 128K. 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 GPT-5.3 Chat 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 GPT-5.3 Chat costs $1.75/M input tokens. GPT-5.3 Chat is $2.25/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 GPT-5.3 Chat 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
GPT-5.3 Chat logoQwen3.8 Max Prime logo
GPT-5.3 Chat 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
GPT-5.3 Chat logoQwen3.8 Omni Flash logo
GPT-5.3 Chat vs Qwen3.8 Omni FlashLanded Sep 2026
Claude Opus 5.5 logoCommand A+ logo
Claude Opus 5.5 vs Command A+Landed Sep 2026
GPT-5.3 Chat logoGPT-6 Luna Pro logo
GPT-5.3 Chat 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
GPT-5.3 Chat logoGPT-6 Luna logo
GPT-5.3 Chat 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
GPT-5.3 Chat logoGPT-6 Sol Pro logo
GPT-5.3 Chat vs GPT-6 Sol ProSame lab
GPT-5.3 Chat logoGPT-6 Sol logo
GPT-5.3 Chat vs GPT-6 SolSame lab
Claude Opus 5.5 logoGPT-5.6 Sol logo
Claude Opus 5.5 vs GPT-5.6 SolCross-provider
Claude Opus 5.5 logoGPT-5.6 Terra logo
Claude Opus 5.5 vs GPT-5.6 TerraSame size
Claude Opus 5.5 logoGPT-6 Astra logo
Claude Opus 5.5 vs GPT-6 AstraCross-provider
Claude Opus 5.5 logoGPT-6 Astra Pro logo
Claude Opus 5.5 vs GPT-6 Astra ProCross-provider

Model pages

Claude Opus 5.5 logo
Claude Opus 5.519 outputs, specs and price
GPT-5.3 Chat logo
GPT-5.3 Chat53 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