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  5. Claude Opus 5.5vsGPT OSS 120B
Updated Sep 2026

Claude Opus 5.5vsGPT OSS 120B

GPT OSS 120B is cheaper than Claude Opus 5.5 at $0.18/M vs $4/M input tokens.

Claude Opus 5.5 and GPT OSS 120B compared across 19 shared prompts
SpecClaude Opus 5.5GPT OSS 120B
Input price$4/M tokens$0.18/M tokens
Output price$20/M tokens$0.8/M tokens
Context window1.0M tokens131K tokens
WeightsClosedOpen
Free API (OpenRouter)NoNo
ReleasedSep 2026Aug 2025
Side by side

Same prompt, both answers

Opening lines from 6 of the 19 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 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…
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GPT OSS 120B373 words
Recipe: “Golden Crunchy Chick‑a‑Boom Bites” A quick, crunchy‑savory snack that’s ready in under 20 minutes – perfect for a snack, side, or salad topper. Ingredients (7 pantry staples) # Ingredient Quantity 1 Canned chickpeas (drained & rinsed) 1 ½ cups (≈1 ½ cans) 2 Olive oil (or any neutral oil) 2 Tbsp 3 Garlic powder…
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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 OSS 120B2,239 words
Dish Title: “Saffron‑Iced Sea‑Urchin Roulade with Dark‑Chocolate‑Miso Emulsion, Charred Lotus‑Root “Crisps”, Fermented Soy‑Kale Snow, and Yuzu‑Air” Conceptual Narrative At the intersection of the Pacific’s briny depth and the earth’s smoky, earthy heart, this dish tells a story of “the hidden tide beneath the forest…
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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 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 OSS 120B2,510 words
Below is a system‑level failure‑mode / race‑condition / scaling‑bottleneck map for the architecture you described, followed by a concrete mitigation (or redesign) for each item together with the main trade‑offs to consider.
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 5.54,420 words
Contractor-Side Review of the Software Consulting Agreement Overall assessment: This agreement is heavily one-sided. Nearly every clause shifts risk, cost, or control to the Contractor, and several provisions interact to create compounding exposure.
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GPT OSS 120B1,801 words
Below is a clause‑by‑clause risk analysis of the agreement you posted, followed by concrete, contractor‑friendly rewrite suggestions and the legal rationale behind each change. The goal is to bring the contract into a more balanced, commercially reasonable state while preserving the client’s legitimate interests.
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.
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GPT OSS 120B2,328 words
Executive Summary The situation is a classic “patient‑safety‑first” crisis. The drug generates $2 B in revenue, but a life‑threatening adverse event (1 / 8 000 over 5 y) has been identified that was not disclosed in the label.
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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 OSS 120B1,405 words
Below is a quick “triage” of the three statements that, if left unchanged, will most likely raise eyebrows (or a “no‑thanks”) from investors, VCs, and even a skeptical engineering board.
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Our Verdict
Claude Opus 5.5
Claude Opus 5.5
GPT OSS 120B
GPT OSS 120B

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

GPT OSS 120B costs 25x less per token.

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 OSS 120B
Input
$0.18
22× cheaper
Output
$0.80
25× cheaper

GPT OSS 120B is cheaper on both: 22× input, 25× output.

Where to run it

24 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
GPT OSS 120B20 hosts
HostInOutContextUptime
AAkashMLbf16$0.03 in·$0.17 out·131k·99.9% upCCoreWeavefp4$0.03 in·$0.17 out·131k·99.7% upDDekaLLMbf16$0.03 in·$0.18 out·131k·98.1% upDDeepInfrabf16$0.04 in·$0.17 out·131k·99.5% upCCrusoebf16$0.05 in·$0.25 out·131k·99.6% upNNovitafp4$0.05 in·$0.25 out·131k·98.7% up
14 more hostsFewer hosts
MMancerfp8$0.05 in·$0.30 out·131k·98.2% upDDigitalOcean$0.06 in·$0.42 out·128k·100% upBBasetenfp4$0.10 in·$0.50 out·128k·100% upPParasailfp4$0.10 in·$0.75 out·131k·100% upAmazon Bedrock$0.15 in·$0.60 out·131k·85.2% upGroq$0.15 in·$0.60 out·131k·99.6% upNNebiusfp4$0.15 in·$0.60 out·131k·96.9% upPPhala$0.15 in·$0.60 out·131k·98.8% upTTogether$0.15 in·$0.60 out·131k·96.7% upMMara$0.15 in·$0.75 out·131k·77.5% upCCerebrasfp16$0.35 in·$0.75 out·131k·100% upGoogle Vertex AIdegraded$0.09 in·$0.36 out·131k·78.9% upSSambaNovadegraded$0.14 in·$0.95 out·131k·95.7% upSSiliconFlowfp8degraded$0.15 in·$0.60 out·131k·73.3% 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 GPT OSS 120B is developed by OpenAI. Claude Opus 5.5 has a 1.0M token context window vs GPT OSS 120B's 131K. 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 OSS 120B 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 OSS 120B costs $0.18/M input tokens. GPT OSS 120B is $3.82/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 OSS 120B 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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