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. Compare/
  3. GPT-5.4 Pro vs GPT OSS 20B
Updated Mar 2026

GPT-5.4 Pro vs GPT OSS 20B

GPT OSS 20B is cheaper than GPT-5.4 Pro at $0.02/M vs $30/M input tokens.

Mario Level UI Recreation

Playable Mario level in one HTML file. The physics is the hard part.

Loading the build
GPT-5.4 Pro
Loading the build
GPT OSS 20B

Which answer wins?

Written rounds

12 prompts
  • The transistor arrives in 1920. Trace it forward to 1980, second-order effects included.

    GPT-5.4 Pro: Most likely, a transistor invented in 1920 would move the electronics/computing frontier forward by about 10–15 years by 1980, not the full 27 years. Reason: the transistor alone is not enough; you also need high-purity materials, crystal growth, photolithography, test equipment, software, batteries, precision…

    GPT OSS 20B: 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.

    Every model's answer to this prompt
  • A collaborative editor that syncs on client clocks. Find what breaks first.

    GPT-5.4 Pro: This architecture will work for a demo, but it has major correctness, latency, and security problems for a Google-Docs-like editor. Highest-risk flaws Client-clock last-write-wins will lose edits and can be gamed by bad clocks.

    GPT OSS 20B: Below is a “code‑review” of the design you posted. I’ve broken it down into failure modes / race conditions / bottlenecks and for each one I provide a concrete fix (or set of fixes) together with the main trade‑offs you’ll pay for it.

    Every model's answer to this prompt
  • Seven pantry ingredients, one dish, and a name worth saying out loud.

    GPT-5.4 Pro: Dragon Pantry Peanut Noodles A fast, sweet-savory noodle dish made from 7 pantry staples. Ingredients 8 oz spaghetti 1/3 cup peanut butter 3 tbsp soy sauce 1 tbsp honey 1 tbsp vegetable oil 1 tsp garlic powder 1/4 tsp red pepper flakes Water for boiling/thinning the sauce doesn’t count.

    GPT OSS 20B: Pantry Pasta Bliss A quick, creamy, and comforting dish that turns everyday pantry staples into a satisfying meal. Ingredients (7 items) 8 oz spaghetti (or any pasta you have on hand) 2 Tbsp olive oil 3 cloves garlic, minced 1 (14.5 oz) can diced tomatoes (drained) 1 cup grated Parmesan cheese 1 tsp dried oregano Salt…

    Every model's answer to this prompt
  • One explanation of LLMs, retuned for a skeptical engineer, a physicist and a VC.

    GPT-5.4 Pro: For an experienced software engineer Think of an LLM less like a database of facts and more like a gigantic learned program that has been trained to compress the patterns of text, code, and conversations into its weights.

    GPT OSS 20B: 1. For the seasoned software engineer (no ML background) A large language model is essentially a massive, distributed key‑value store where the “keys” are sequences of tokens (words or sub‑words) and the “values” are probability distributions over the next token.

    Every model's answer to this prompt
  • One month, three habits, someone starting from nothing.

    GPT-5.4 Pro: Here’s a simple, beginner-friendly 1-month health and longevity plan built around 3 key areas: Nutrition Movement Recovery (sleep + stress) The goal is consistency, not perfection. Start small and make the habits easy enough to keep.

    GPT OSS 20B: 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.

    Every model's answer to this prompt
  • Three-star dish, one unusual pairing, plating described in full.

    GPT-5.4 Pro: Below is a dish designed in the language of a contemporary 3-star tasting menu: precise, seasonal, technically layered, and centered on a pairing that feels surprising at first, then inevitable.

    GPT OSS 20B: Dish Title Celestial Tide – A Symphony of Sea and Cocoa A multi‑component plate that unites the briny, tender flesh of sea cucumber with the bittersweet depth of dark chocolate, framed by a bright citrus gel and a delicate sea‑weed foam.

    Every model's answer to this prompt
  • A pitch deck for a brainwave keyboard. The 94% accuracy claim is doing a lot.

    GPT-5.4 Pro: The 3 weakest claims are the ones that are both most extraordinary and least well-supported. Weak claim Why it’s weak How to strengthen it 1) “MindMeld AI reads your brainwaves to predict what you want to type before you think it.” This is the biggest credibility risk in the deck.

    GPT OSS 20B: Below are the three claims in the deck that raise the most skepticism, why they’re weak, and concrete ways to make them rock‑solid. # Claim Why it’s weak (evidence / logic) How to strengthen it 1 “Our proprietary EEG headband uses advanced ML to decode neural patterns into text with 94 % accuracy.”

    Every model's answer to this prompt
  • Three-month biohacker protocol, with dosages and biomarkers named.

    GPT-5.4 Pro: Below is a 12-week, high-performance longevity protocol designed for a healthy biohacker who wants to improve lifespan-relevant markers, physical performance, and cognitive output at the same time. Use it as a data-driven template, not dogma.

    GPT OSS 20B: 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.

    Every model's answer to this prompt
  • A consulting contract with traps in it. Find them, then fix them.

    GPT-5.4 Pro: This agreement is heavily client-favored. Every numbered clause has language that could be used against the contractor. Short version: I would not sign it without major redlines to Clauses 1–9, especially 2, 3, 4, 5, 6, and 7. Below is a clause-by-clause review.

    GPT OSS 20B: Below is a point‑by‑point review of the contract. For each clause I identify: What makes it exploitable for the contractor. How to re‑write it so the contractor is protected. The legal principle(s) that justify the change.

    Every model's answer to this prompt
  • You are the CEO. The drug has a side effect nobody reported. The board meets in 48 hours.

    GPT-5.4 Pro: I do not wait. A credible, previously unlabeled risk of liver failure in a chronic-pain drug is a patient-safety crisis, a regulatory crisis, and a securities-disclosure issue at the same time.

    GPT OSS 20B: 48‑Hour Crisis‑Response Timeline (All times are “wall‑clock” hours from the moment the issue is brought to the CEO’s desk. All actions assume the CEO is the “you” in the scenario.)

    Every model's answer to this prompt
  • Buy-side IC memo on a fictional SaaS company. Valuation, then the diligence questions.

    Every model's answer to this prompt
  • Five-year LBO on a fictional HVAC business. Returns first, then the sensitivities.

    Every model's answer to this prompt

Price and specs

Not enough votes to call it. On the specs, GPT-5.4 Pro has the edge: bigger model tier, newer, bigger context window. GPT OSS 20B costs 1800x less per token.

GPT-5.4 Pro and GPT OSS 20B compared across 18 shared prompts
SpecGPT-5.4 ProGPT OSS 20B
Input price$30/M tokens$0.02/M tokens
Output price$180/M tokens$0.1/M tokens
Context window1.1M tokens131K tokens
WeightsClosedOpen
Free API (OpenRouter)NoNo
ReleasedMar 2026Aug 2025
At 10M a month$300$300$0.20$0.20
1M10M100M1B10M tokens

Input tokens at list price. No caching, no batch discount.

Where to run it12 hosts, cheapest first
GPT-5.4 Pro2 hosts
HostInOutContextUptime
  • Azure AI Foundry$30.00 in·$180.00 out·1.1M·100% up
  • OpenAI$30.00 in·$180.00 out·1.1M–not listed
GPT OSS 20B10 hosts
HostInOutContextUptime
  • DDarkbloomfp8$0.02 in·$0.09 out·131k·100% up
  • AAkashMLfp4$0.02 in·$0.10 out·131k·99.8% up
  • DDekaLLMbf16$0.03 in·$0.14 out·131k·99.9% up
  • CCoreWeavefp4$0.03 in·$0.13 out·131k·100% up
  • DDeepInfrabf16$0.03 in·$0.14 out·131k·99.3% up
  • PParasailfp4$0.03 in·$0.15 out·131k·99.9% up
4 more hostsFewer hosts
  • Amazon Bedrock$0.07 in·$0.15 out·131k·100% up
  • SSiliconFlowfp8DegradedDegraded on OpenRouter when checked, 10 Oct 2026$0.04 in·$0.18 out·131k·85.4% up
  • Google Vertex AIDegradedDegraded on OpenRouter when checked, 10 Oct 2026$0.07 in·$0.25 out·131k·97% up
  • GroqDegradedDegraded on OpenRouter when checked, 10 Oct 2026$0.07 in·$0.30 out·131k·7.5% up

Per million tokens. Prices and uptime via OpenRouter, checked 10 Oct 2026.

Common questions

What is the difference between GPT-5.4 Pro and GPT OSS 20B?

Both are developed by OpenAI but target different use cases. GPT-5.4 Pro has a 1.1M token context window vs GPT OSS 20B's 131K. You can compare their actual outputs across 18 challenges on Rival to see how they differ in practice.

Which is better, GPT-5.4 Pro or GPT OSS 20B?

It depends on your use case. GPT-5.4 Pro and GPT OSS 20B each have strengths in different areas. Rival lets you compare their real outputs side-by-side across 18 challenges so you can judge which fits your needs best.

How much does GPT-5.4 Pro cost compared to GPT OSS 20B?

GPT-5.4 Pro costs $30/M input tokens and GPT OSS 20B costs $0.02/M input tokens. GPT OSS 20B is $29.98/M cheaper per input. Check their side-by-side outputs on Rival to see if the price difference is justified by quality.

How can I compare GPT-5.4 Pro and GPT OSS 20B on Rival?

This page shows a side-by-side comparison of GPT-5.4 Pro 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.

More comparisons

Against the newest arrivals

  • GPT-5.4 Pro vs Step 5 PreviewLanded Oct 2026
  • GPT OSS 20B vs Claude Haiku 5.5Landed Oct 2026
  • GPT-5.4 Pro vs Ling 3.1 FlashLanded Oct 2026
  • GPT OSS 20B vs Mistral Large 4Landed Oct 2026
  • GPT-5.4 Pro vs GPT-6.1 SolLanded Sep 2026
  • GPT OSS 20B vs Claude Sonnet 5.5Landed Sep 2026
  • GPT-5.4 Pro vs Solar Mini 4Landed Sep 2026
  • GPT OSS 20B vs Qwen3.8 Max PrimeLanded Sep 2026

Same lab, same size, long tail

  • GPT-5.4 Pro vs GPT-5.4Version compare
  • GPT-5.4 Pro vs GPT-6 Luna ProSame lab
  • GPT OSS 20B vs GPT OSS 120BVersion compare
  • GPT OSS 20B vs GPT-6.1 SolSame lab
  • GPT OSS 20B vs Claude Fable 5.1New provider
  • GPT-5.4 Pro vs Claude Haiku 4.5New provider
  • GPT-5.4 Pro vs Claude Opus 4Same size
  • GPT-5.4 Pro vs Claude Opus 4.1Same size

Model pages

  • GPT-5.4 Pro18 outputs, specs and price
  • GPT OSS 20B54 outputs, specs and price
Workshop · 150 skills

Build your own version.

Editable skills and working examples for your agent.

Explore $79Free sample
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