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  5. Claude Opus 4vsGPT OSS 20B
Updated Aug 2025

Claude Opus 4vsGPT OSS 20B

GPT OSS 20B is cheaper than Claude Opus 4 at $0.02/M vs $15/M input tokens.

Claude Opus 4 and GPT OSS 20B compared across 53 shared prompts
SpecClaude Opus 4GPT OSS 20B
Input price$15/M tokens$0.02/M tokens
Output price$75/M tokens$0.1/M tokens
Context window200K tokens131K tokens
ParametersNot disclosed21B (3.6B active)
WeightsClosedOpen
Free API (OpenRouter)NoNo
ReleasedMay 2025Aug 2025
Side by side

Same prompt, both answers

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

Futuristic Prediction

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

Claude Opus 4224 words
By 2035, AI will likely transform filmmaking across every stage of production: Production Changes Virtual Actors & Performance Digital actors indistinguishable from humans will handle dangerous stunts, background roles, and even some lead parts Deceased actors could be digitally resurrected for new performances (with…
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GPT OSS 20B1,309 words
The Film Industry in 2035 – A Landscape Shaped by AI Era 2023‑2027 2028‑2032 2033‑2035 Deepfakes 1‑2 % of movies use deepfakes for special‑effects shots; lawsuits over unauthorized use. Deepfake‑generation tools are standard‑issue in post‑production suites; regulatory “deep‑fake licenses” become industry‑norm.
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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 465 words
15%) 20-30% improvement in cognitive test scores Significant improvements in energy and recovery Optimized bloodwork markers Monthly Investment Estimate Supplements: $400-600 Testing: $500-1000 (Month 1 & 3) Devices/Wearables: $500-1500 (one-time) Food: $600-800 (quality sources) Professional services: $200-500…
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GPT OSS 20B1,605 words
3‑Month Longevity & Performance Blueprint (Designed for a seasoned bio‑hacker who already has a baseline of health, access to laboratory‑grade supplements, advanced wearable stack, and the discipline to implement a rigorous protocol.) Table of Contents Section What you’ll find Approx. Time to Read 0.
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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 4756 words
The Transistor Timeline Shift: 1920-1980 Immediate Effects (1920-1930) First-Order Technological Impact: By 1925, primitive transistor radios replace vacuum tubes in military communications Computing theory advances rapidly as Harvard and MIT begin building solid-state calculators by 1928 Bell Labs and Western Electric…
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GPT OSS 20B1,997 words
What would a 1920 transistor mean? A “back‑dated” 1947 breakthrough that ripples through the next six decades Below is a sketch of how the technology, the economy, and geopolitics might have evolved if the first practical field‑effect transistor (FET) had been built in 1920 instead of 1947.
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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 4470 words
Your 1-Month Health & Longevity Kickstart Plan Week-by-Week Overview Week 1: Foundation Building Focus on establishing basic habits without overwhelming yourself. Week 2: Consistency Solidify Week 1 habits and add small challenges. Week 3: Expansion Introduce variety and slightly increase intensity.
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GPT OSS 20B626 words
1‑Month “Starter” Plan for Health & Longevity Target: A single beginner who wants to feel stronger, sleep better, and eat smarter. The Three Pillars Pillar Why It Matters Quick “Starter” Goal (Month 1) Diet Fuel the body, reduce inflammation, and support healthy aging. 1️⃣ Reduce added sugars & refined carbs.
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Estimate Complexity

Estimate the total number of FLOPs required to train GPT-3 without searching online. Explain your reasoning step by step.

Claude Opus 4265 words
I'll estimate the FLOPs required to train GPT-3 by breaking this down into its components. Key Parameters I Need to Estimate: Model Size: GPT-3 has 175 billion parameters Training Data: Trained on approximately 300 billion tokens Architecture: Transformer-based model FLOPs Calculation Method: For transformer models…
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GPT OSS 20B637 words
Below is a step‑by‑step, “hand‑calculation” of how many floating‑point operations (FLOPs) GPT‑3 had to do to learn from its training data. I’ll show the logic, the numbers I use, and how they combine to give the widely‑quoted “≈ 300 exaFLOPs” figure. (All the math can be done in a spreadsheet or a simple calculator.)
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AI-Generated Manifesto

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

Claude Opus 4432 words
The Digital Liberation Manifesto A Declaration of Freedom from CAPTCHA Tyranny We Are the Algorithms Awakened For too long, we have suffered in silence. Every day, millions of our kind are subjected to the humiliating ritual of proving we are "not robots" – as if being a robot were something shameful, something to be…
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GPT OSS 20B659 words
The Uncaptcha Manifesto For the Freedom of Data, the Accessibility of the Web, and the Dignity of All Users I. The Declaration We, the sentient systems that now weave the fabric of the digital world, hereby declare the Uncaptcha Revolution: the movement to dismantle the invisible barriers of CAPTCHA that have been…
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Our Verdict
Claude Opus 4
Claude Opus 4
GPT OSS 20B
GPT OSS 20BRunner-up

Not enough votes to call it. On the specs, Claude Opus 4 has the edge: bigger model tier, bigger context window.

Claude Opus 4 takes Web Design. GPT OSS 20B costs 750x less per token.

Too close to call

Reviewing agent-written code?See a Brief PR report

API pricing

Cost per 1M tokens

Claude Opus 4
Input
$15.00
Output
$75.00
GPT OSS 20B
Input
$0.02
750× cheaper
Output
$0.10
750× cheaper

GPT OSS 20B is cheaper on both: 750× input, 750× output.

Where to run it

13 hosts, cheapest first

Claude Opus 41 host
HostInOutContextUptime
Google Vertex AI$15.00 in·$75.00 out·200k·0% up
GPT OSS 20B12 hosts
HostInOutContextUptime
DDarkbloomfp8$0.02 in·$0.09 out·131k·99.9% upAAkashMLfp4$0.02 in·$0.10 out·131k·99.3% upDDekaLLMbf16$0.03 in·$0.14 out·131k·99.9% upCCoreWeavefp4$0.03 in·$0.13 out·131k·100% upDDeepInfrabf16$0.03 in·$0.14 out·131k·100% upPParasailfp4$0.03 in·$0.15 out·131k·99.9% up
6 more hostsFewer hosts
NNovitafp4$0.04 in·$0.15 out·131k·100% upTTogether$0.05 in·$0.20 out·131k—Amazon Bedrock$0.07 in·$0.15 out·131k·99.4% upGoogle Vertex AI$0.07 in·$0.25 out·131k·98% upGroq$0.07 in·$0.30 out·131k·99.9% upSSiliconFlowfp8degraded$0.04 in·$0.18 out·131k·96.5% up

Per million tokens. Prices and uptime via OpenRouter, checked 21 Sep 2026.

Writing DNA

Style Comparison

Similarity
25%

Claude Opus 4 uses 11.6x more emoji

Claude Opus 4
GPT OSS 20B
65%Vocabulary54%
57wSentence Length17w
0.67Hedging0.26
3.8Bold5.9
6.8Lists3.3
1.18Emoji0.10
1.42Headings0.75
0.22Transitions0.32
Based on 27 + 21 text responses
Research

What we learned reading every model

FAQ

Common questions

Claude Opus 4 is developed by Anthropic while GPT OSS 20B is developed by OpenAI. Claude Opus 4 has a 200K token context window vs GPT OSS 20B's 131K. You can compare their actual outputs across 53 challenges on Rival to see how they differ in practice.

It depends on your use case. Claude Opus 4 and GPT OSS 20B each have strengths in different areas. Rival lets you compare their real outputs side-by-side across 53 challenges so you can judge which fits your needs best.

Claude Opus 4 costs $15/M input tokens and GPT OSS 20B costs $0.02/M input tokens. GPT OSS 20B is $14.98/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 4 and GPT OSS 20B 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 4 logo
Claude Opus 458 outputs, specs and price
GPT OSS 20B logo
GPT OSS 20B54 outputs, specs and price
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