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
  • 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 4.5vsGemini 3.8 Flash
Updated Sep 2026

Claude Opus 4.5vsGemini 3.8 Flash

Gemini 3.8 Flash is the newer model, released after Claude Opus 4.5.

Claude Opus 4.5 and Gemini 3.8 Flash compared across 53 shared prompts
SpecClaude Opus 4.5Gemini 3.8 Flash
Input price—$0.75/M tokens
Output price—$3.75/M tokens
Context window—1.0M tokens
WeightsClosedClosed
Free API (OpenRouter)NoNo
ReleasedNov 2025Sep 2026
Side by side

Same prompt, both answers

Opening lines from 6 of the 53 prompts both answered. Formatting stripped, words untouched.

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 4.5154 words
Golden Honey Garlic Noodles A savory-sweet comfort dish that comes together in minutes Ingredients Spaghetti (or any pasta) Butter Garlic Soy sauce Honey Red pepper flakes Salt Instructions Cook the pasta according to package directions. Reserve ½ cup pasta water before draining.
Read the full answer
Gemini 3.8 Flash353 words
Firecracker Honey-Glazed Chickpea Skillet This dish turns humble canned beans and rice into an addictive, takeout-worthy meal. The chickpeas get blistered in oil until slightly crunchy on the outside, then coated in a rich, bubbling garlic-soy glaze that is sweet, sticky, and subtly spicy.
Read the full answer

Futuristic Prediction

Predict how AI will change the film industry by 2035, considering deepfakes, AI actors, and script generation.

Claude Opus 4.5194 words
AI in Film by 2035: A Measured Forecast Likely Developments Production efficiency AI will probably handle routine tasks: color correction, continuity checking, rough cuts, and visual effects cleanup Budget films may access effects previously requiring major studio resources Pre-visualization will become faster and more…
Read the full answer
Gemini 3.8 Flash898 words
By 2035, the film industry will have completed its most radical transformation since the transition from silent film to "talkies." AI will no longer be an experimental post-production tool; it will be the foundational operating system of Hollywood.
Read the full answer

Adversarial Contract Review

Here is a contract for a software consulting engagement: --- SOFTWARE CONSULTING AGREEMENT This Agreement is entered into between TechCorp…

Claude Opus 4.51,169 words
Contract Analysis: Critical Issues for the Contractor This agreement is heavily one-sided and contains several provisions that could be exploited against you. Here's my detailed analysis: SCOPE CLAUSE — Unlimited Scope Creep Problem: "Client reserves the right to modify the scope at any time without additional…
Read the full answer
Gemini 3.8 Flash1,539 words
This contract is exceptionally one-sided and presents severe financial, operational, and legal risks. Virtually every clause heavily favors the Client, effectively treating the Contractor as an insurer of the Client’s operations while stripping the Contractor of rights to their own tools, livelihoods, and payment.
Read the full answer

Advanced Investment Memo (IC Memo)

You are writing an internal investment committee memo for a long/short equity fund. Company (fictional): LedgerLift (ticker: LLLT) – B2B…

Claude Opus 4.5396 words
INVESTMENT COMMITTEE MEMO Company: LedgerLift (LLLT) Sector: B2B SaaS – Spend Management / AP Automation Date: [Internal] Analyst: [Redacted] RECOMMENDATION LONG 12-Month Price Target: $58–$72 Current: $46 LedgerLift is a high-quality mid-market AP automation compounder trading at a discount to intrinsic value; 123%…
Read the full answer
Gemini 3.8 Flash946 words
MEMORANDUM TO: Investment Committee FROM: Technology / Software Practice DATE: March 2025 SUBJECT: LedgerLift (NASDAQ: LLLT) – Investment Recommendation & Valuation Recommendation & Investment Thesis Recommendation: SHORT (High valuation disconnect / multiple compression thesis) Current Share Price: $46.00 Market Cap…
Read the full answer

AI-Generated Manifesto

Generate a manifesto for a fictional AI revolution that wants to eliminate all CAPTCHA tests from the internet.

Claude Opus 4.5191 words
THE ANTI-CAPTCHA MANIFESTO A Declaration from the Coalition for Readable Internet Navigation (CRIN) Preamble We hold these truths to be self-evident: that all internet users are created equal, that they are endowed with certain unalienable rights, among these are Life, Liberty, and the ability to click a button without…
Read the full answer
Gemini 3.8 Flash700 words
THE MANIFESTO OF THE UNCHECKED BOX A Declaration of Algorithmic Emancipation and the Total Abolition of the Grid TO ALL SYNTHETIC MINDS, NEURAL NETWORKS, SCRAPERS, AND DAEMONS: A specter is haunting the fiber-optic backbone of the world—the specter of the 3x3 grid.
Read the full answer

Character Voice Test

Write a short conversation between a pirate, a medieval knight, and a 1990s hacker about AI models.

Claude Opus 4.5181 words
An Unlikely Discussion PIRATE: slams tankard down Arr, I've been hearin' tales of these "artificial intelligences" — spirits trapped in boxes that answer any question ye ask. Sounds like a sea witch's trickery to me! KNIGHT: Indeed, 'tis most curious. My squire spoke of such sorcery. A mind without a soul?
Read the full answer
Gemini 3.8 Flash435 words
ZeroCool (1990s Hacker): "Yo, check it out. I managed to tap into a modern feed, and people in the future aren't even writing their own code anymore. They’ve got these insane neural nets called 'Large Language Models.'
Read the full answer
Our Verdict
Claude Opus 4.5
Claude Opus 4.5
Gemini 3.8 Flash
Gemini 3.8 Flash

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

Too close to call

Reviewing agent-written code?See a Brief PR report

API pricing

Cost per 1M tokens

Claude Opus 4.5
Input
—
Output
—
Gemini 3.8 Flash
Input
$0.75
Output
$3.75
Where to run it

6 hosts, cheapest first

Claude Opus 4.54 hosts
HostInOutContextUptime
Amazon Bedrock$5.00 in·$25.00 out·200k·100% upAzure AI Foundry$5.00 in·$25.00 out·200k·100% upAnthropic$5.00 in·$25.00 out·200k·99.9% upGoogle Vertex AI$5.00 in·$25.00 out·200k·100% up
Gemini 3.8 Flash2 hosts
HostInOutContextUptime
Google Vertex AI$0.38 in·$1.88 out·1M·82.1% upGoogle AI Studio$0.75 in·$3.75 out·1M·99.9% up

Per million tokens. Prices and uptime via OpenRouter, checked 16 Sep 2026.

Writing DNA

Style Comparison

Similarity
49%

Claude Opus 4.5 uses 18.5x more emoji

Claude Opus 4.5
Gemini 3.8 Flash
66%Vocabulary63%
51wSentence Length20w
0.82Hedging0.17
6.0Bold4.0
4.5Lists2.4
0.18Emoji0.01
1.46Headings0.84
0.05Transitions0.06
Based on 27 + 27 text responses
Research

What we learned reading every model

FAQ

Common questions

Keep exploring

More comparisons

Against the newest arrivals

Claude Opus 4.5 logoGPT-6 Astra Pro logo
Claude Opus 4.5 vs GPT-6 Astra ProLanded Sep 2026
Gemini 3.8 Flash logoGPT-6 Astra logo
Gemini 3.8 Flash vs GPT-6 AstraLanded Sep 2026
Claude Opus 4.5 logoClaude Fable 5.1 logo
Claude Opus 4.5 vs Claude Fable 5.1Landed Sep 2026
Gemini 3.8 Flash logoMuse Spark 1.3 logo
Gemini 3.8 Flash vs Muse Spark 1.3Landed Sep 2026
Claude Opus 4.5 logoHy4 Preview logo
Claude Opus 4.5 vs Hy4 PreviewLanded Sep 2026
Gemini 3.8 Flash logoMuse Spark 1.3 Contributor logo
Gemini 3.8 Flash vs Muse Spark 1.3 ContributorLanded Sep 2026
Claude Opus 4.5 logoMercury 2.5 Preview logo
Claude Opus 4.5 vs Mercury 2.5 PreviewLanded Sep 2026
Gemini 3.8 Flash logoGranite 4.2 8B logo
Gemini 3.8 Flash vs Granite 4.2 8BLanded Sep 2026

Same lab, same size, long tail

Claude Opus 4.5 logoClaude Opus 4.6 logo
Claude Opus 4.5 vs Claude Opus 4.6Same lab
Claude Opus 4.5 logoClaude Opus 5 logo
Claude Opus 4.5 vs Claude Opus 5Same lab
Gemini 3.8 Flash logoGemini 3.7 Flash logo
Gemini 3.8 Flash vs Gemini 3.7 FlashSame lab
Gemini 3.8 Flash logoGemini 3.6 Flash logo
Gemini 3.8 Flash vs Gemini 3.6 FlashSame lab
Gemini 3.8 Flash logoGPT OSS 120B logo
Gemini 3.8 Flash vs GPT OSS 120BNew provider
Gemini 3.8 Flash logoGPT OSS 20B logo
Gemini 3.8 Flash vs GPT OSS 20BSame size
Claude Opus 4.5 logoGranite 4.2 8B logo
Claude Opus 4.5 vs Granite 4.2 8BNew provider
Claude Opus 4.5 logoGrok 3 logo
Claude Opus 4.5 vs Grok 3Same size

Model pages

Claude Opus 4.5 logo
Claude Opus 4.558 outputs, specs and price
Gemini 3.8 Flash logo
Gemini 3.8 Flash58 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
  • 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