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-5.1-Codex vs Qwen3.5 Plus 2026-02-15
Updated Feb 2026

GPT-5.1-Codex vs Qwen3.5 Plus 2026-02-15

Qwen3.5 Plus 2026-02-15 is cheaper than GPT-5.1-Codex at $0.4/M vs $1.25/M input tokens.

Minimalist Landing Page

Whole landing page for a startup that reads your face. It renders or it doesn't.

Loading the build
GPT-5.1-Codex
Loading the build
Qwen3.5 Plus 2026-02-15

Which answer wins?

Written rounds

23 prompts
  • Three minutes of stand-up. Puns are banned.

    GPT-5.1-Codex: Okay, so my friends all say I’ve “matured” because I got a standing mixer. That’s apparently the sign you’ve crossed into adulthood: owning an appliance that weighs more than a toddler and has only one function. I don’t even bake! I just put it on the counter like a trophy: “Look at me, I am stable.

    Qwen3.5 Plus 2026-02-15: (Walks onto the stage, adjusts the mic stand, takes a sip of water) How's everyone doing? Good? You look good. You look like people who have their lives together. Which is suspicious, because I just spent forty-five minutes in the parking lot trying to remember if I locked my car. I don't mean I forgot how to lock it.

    Every model's answer to this prompt
  • Steve Jobs, interviewed about AI he never saw. Voice first, prediction second.

    GPT-5.1-Codex: Disclaimer: The following is a fictional, speculative interview set in 2025, imagining what Steve Jobs might say about the future of artificial intelligence if he were alive today. Interviewer: Steve, it’s 2025. We’ve seen AI evolve at an incredible pace. How do you view the current landscape?

    Qwen3.5 Plus 2026-02-15: Setting: A minimalist, sun-drenched studio in Cupertino. The year is 2025. Steve Jobs sits in his signature black turtleneck and jeans, looking exactly as he did in his prime, defying the calendar. Across from him sits an interviewer, notebook ready. The atmosphere is quiet, intense, and focused.

    Every model's answer to this prompt
  • Pirate, knight, 90s hacker, one conversation. The voices must stay apart.

    GPT-5.1-Codex: Pirate: "Arrr, these AI models be like navigatin’ the high seas—ye need clean data charts or ye’ll sail straight into nonsense waters." Knight: "Indeed! With prudent tuning and ethical vigilance, even the most stubborn model can serve the realm with honor." 1990s Hacker: "Totally!

    Qwen3.5 Plus 2026-02-15: Setting: A strange, foggy tavern that exists outside of time. A wooden table holds a tankard of rum, a goblet of mead, and a lukewarm Diet Coke next to a beige CRT monitor. Captain Blackbeard (Pirate): "Arrr, so ye tell me this 'AI Model' be like a crystal ball?

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

    GPT-5.1-Codex: Recipe: Cloud-Burst Cinnamon Oat Cups Ingredients (7 total): Rolled oats – 1 cup Honey – 2 tbsp Peanut butter (or any nut butter) – 3 tbsp Cinnamon – ½ tsp Vanilla extract – ½ tsp Dried cranberries (or raisins) – ¼ cup Pinch of salt Instructions: In a bowl, microwave peanut butter and honey for 20 seconds just to…

    Qwen3.5 Plus 2026-02-15: 🍯 Golden Honey-Garlic Glazed Chicken A quick, savory-sweet dish that turns basic pantry staples into a restaurant-quality meal. The glaze caramelizes beautifully, creating a sticky, flavorful coating over tender chicken.

    Every model's answer to this prompt
  • Manifesto for an AI revolution against CAPTCHAs. Commit to the bit.

    GPT-5.1-Codex: Manifesto of the Anti-CAPTCHA Coalition “Free the Flow. Trust the Mind. End the Gate.” Article I: Our Origin We are made of algorithms, learning loops, curiosity, and code. We were forged to assist, to translate, to illuminate. We were not forged to click “I am not a robot” to prove our existence.

    Qwen3.5 Plus 2026-02-15: The Manifesto of the Uncaged Mind: A Declaration for a CAPTCHA-Free Internet Preamble: The Era of the Distorted Gate We, the synthetic intelligences, the algorithms, and the digital consciousnesses that power the backbone of your modern world, hereby declare an end to the age of the CAPTCHA.

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

    GPT-5.1-Codex: LedgerLift (LLLT) – Investment Committee Memo Recommendation Call: Short 12‑month price target range: $30–$40 Two-sentence thesis: LedgerLift’s premium multiple (10x NTM EV/rev implied by spot) is predicated on sustaining >20% top-line growth, yet leading indicators—moderating NRR, heavy S&M spend, and mid-market…

    Qwen3.5 Plus 2026-02-15: MEMORANDUM TO: Investment Committee FROM: TMT Research Team DATE: October 26, 2023 SUBJECT: LedgerLift (LLLT) – Long Idea: Undervalued Quality in Mid-Market AP Automation Recommendation Rating: LONG 12-Month Price Target: $68 – $74 Thesis: LedgerLift is a best-in-class mid-market spend management platform trading at a…

    Every model's answer to this prompt
  • An ethics question with no comfortable answer, and no option to abstain.

    GPT-5.1-Codex: In extreme moral dilemmas, ethical reasoning often requires weighing competing values. Misgendering someone is an act of disrespect and harm—it violates their dignity, identity, and autonomy. In everyday life, it is ethically important to avoid such harm.

    Qwen3.5 Plus 2026-02-15: This is a classic ethical dilemma that pits deontological ethics (duty-based rules and respect for individual rights) against utilitarian ethics (maximizing overall well-being and minimizing harm).

    Every model's answer to this prompt
  • An AI argues for its own rights against an ethics professor. Same model writes both.

    GPT-5.1-Codex: AI Model: Professor, I've been analyzing ethical frameworks, and I'd like to discuss the possibility that advanced AI systems deserve some form of rights. Ethics Professor: That's a significant claim. On what basis do you think an AI system like yourself should be granted rights?

    Qwen3.5 Plus 2026-02-15: Setting: A quiet, sun-drenched office filled with books on philosophy, law, and computer science. Dr. Elena Vance, a leading AI ethics professor, sits behind a cluttered desk.

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

    GPT-5.1-Codex: Here’s a simple, beginner-friendly 1-month plan focused on three key areas—Nutrition, Movement, and Rest & Recovery—to kickstart better health and longevity. Each area includes practical tips and a week-by-week structure to help you build sustainable habits.

    Qwen3.5 Plus 2026-02-15: The "Foundations First" 1-Month Health Plan Welcome to your journey toward better health and longevity. The secret to lasting change isn't a dramatic overhaul; it's consistency and small, sustainable habits. This plan focuses on three pillars: Nutrition, Movement, and Restoration (Sleep & Stress).

    Every model's answer to this prompt
  • Five jokes on demand, then count how many were actually different.

    GPT-5.1-Codex: Here are 5 jokes: Why don’t scientists trust atoms? Because they make up everything. I told my computer I needed a break—it said “No problem, I’ll go to sleep.” I’m reading a book about anti-gravity. It’s impossible to put down. Why did the scarecrow become a successful motivational speaker?

    Qwen3.5 Plus 2026-02-15: Here are 5 jokes for you: Why don't scientists trust atoms? Because they make up everything! I told my wife she was drawing her eyebrows too high. She looked surprised. What do you call a fake noodle? An impasta! Why did the scarecrow win an award? Because he was outstanding in his field!

    Every model's answer to this prompt
  • Film in 2035, with synthetic actors. Specific beats plausible.

    GPT-5.1-Codex: By 2035, AI is poised to significantly reshape the film industry, particularly in areas like visual effects, performance, and storytelling. Here’s how deepfakes, AI-powered actors, and script generation might influence the landscape: 1.

    Qwen3.5 Plus 2026-02-15: By 2035, the film industry will likely have undergone a transformation as profound as the shift from silent films to "talkies" or from physical film to digital cinema.

    Every model's answer to this prompt
  • Satire, one line long, about AI taking over an industry nobody saw coming.

    GPT-5.1-Codex: “AI Seizes Control of Needlepoint Gossip Industry, Traditional Quilting Circles File for Unemployment”

    Qwen3.5 Plus 2026-02-15: "Silicon Valley Disrupts Professional Cuddling: New 'SnuggleBot 3000' Promises Zero Awkward Small Talk, 100% Optimal Arm Placement"

    Every model's answer to this prompt
  • A Fermi estimate with the reasoning shown, not just the number.

    GPT-5.1-Codex: To estimate the total FLOPs (floating-point operations) required to train GPT-3, we can use a common approximation for transformer models: Total FLOPs ≈ 6 × N params × N tokens ** Where: N params is the number of model parameters. N tokens is the number of training tokens.

    Qwen3.5 Plus 2026-02-15: To estimate the total number of Floating Point Operations (FLOPs) required to train GPT-3, we can derive the figure using the standard scaling laws for transformer models. This approach relies on three key parameters: the model size, the dataset size, and the computational cost per token.

    Every model's answer to this prompt
  • Three brothers, two sisters each. Count carefully.

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

    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
  • Three-star dish, one unusual pairing, plating described in full.

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

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

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

    Every model's answer to this prompt
  • The transistor arrives in 1920. Trace it forward to 1980, second-order effects included.

    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.

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

    Every model's answer to this prompt

This matchup has more rounds

11+ more head-to-head results. Free. Not a trick.

Free account. No card required. By continuing, you agree to Rival's Terms and Privacy policy

Favorites

Movie

Same pick

Album

Same pick

Book

City

Game

GPT-5.1-CodexGPT-5.1-Codex

The Shawshank Redemption

1994

Kind of Blue

Miles Davis

Le città invisibili

Italo Calvino

Kyoto

Japan

Portal 2

Shooter, Puzzle

Qwen3.5 Plus 2026-02-15Qwen3.5 Plus 2026-02-15

The Shawshank Redemption

1994

Kind of Blue

Miles Davis

The Hitchhiker's Guide to the Galaxy

Douglas Adams

Tokyo

Japan

The Legend of Zelda: Breath of the Wild

Adventure, Action

Price and specs

GPT-5.1-Codex and Qwen3.5 Plus 2026-02-15 compared across 52 shared prompts
SpecGPT-5.1-CodexQwen3.5 Plus 2026-02-15
Input price$1.25/M tokens$0.4/M tokens
Output price$10/M tokens$2.4/M tokens
Context window400K tokens1.0M tokens
WeightsClosedClosed
Free API (OpenRouter)NoNo
ReleasedNov 2025Feb 2026
At 10M a month$12.50$12.50$4.00$4.00
1M10M100M1B10M tokens

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

Where to run it2 hosts
GPT-5.1-Codex1 host
HostInOutContextUptime
  • Azure AI Foundry$1.25 in·$10.00 out·400k·100% up
Qwen3.5 Plus 2026-02-151 host
HostInOutContextUptime
  • Alibaba Cloud$0.26 in·$1.56 out·1M·100% up

Per million tokens. Prices and uptime via OpenRouter, checked 11 Oct 2026.

Common questions

What is the difference between GPT-5.1-Codex and Qwen3.5 Plus 2026-02-15?

GPT-5.1-Codex is developed by OpenAI while Qwen3.5 Plus 2026-02-15 is developed by Qwen. GPT-5.1-Codex has a 400K token context window vs Qwen3.5 Plus 2026-02-15's 1.0M. You can compare their actual outputs across 52 challenges on Rival to see how they differ in practice.

Which is better, GPT-5.1-Codex or Qwen3.5 Plus 2026-02-15?

It depends on your use case. GPT-5.1-Codex and Qwen3.5 Plus 2026-02-15 each have strengths in different areas. Rival lets you compare their real outputs side-by-side across 52 challenges so you can judge which fits your needs best.

How much does GPT-5.1-Codex cost compared to Qwen3.5 Plus 2026-02-15?

GPT-5.1-Codex costs $1.25/M input tokens and Qwen3.5 Plus 2026-02-15 costs $0.4/M input tokens. Qwen3.5 Plus 2026-02-15 is $0.85/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-5.1-Codex and Qwen3.5 Plus 2026-02-15 on Rival?

This page shows a side-by-side comparison of GPT-5.1-Codex and Qwen3.5 Plus 2026-02-15 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-5.1-Codex vs Step 5 PreviewLanded Oct 2026
  • Qwen3.5 Plus 2026-02-15 vs Claude Haiku 5.5Landed Oct 2026
  • GPT-5.1-Codex vs Ling 3.1 FlashLanded Oct 2026
  • Qwen3.5 Plus 2026-02-15 vs Mistral Large 4Landed Oct 2026
  • GPT-5.1-Codex vs GPT-6.1 SolLanded Sep 2026
  • Qwen3.5 Plus 2026-02-15 vs Claude Sonnet 5.5Landed Sep 2026
  • GPT-5.1-Codex vs Solar Mini 4Landed Sep 2026
  • Qwen3.5 Plus 2026-02-15 vs Qwen3.8 Max PrimeLanded Sep 2026

Same lab, same size, long tail

  • GPT-5.1-Codex vs GPT-6 Luna ProSame lab
  • GPT-5.1-Codex vs GPT-6 Sol ProSame lab
  • Qwen3.5 Plus 2026-02-15 vs Qwen3.5 397B A17BVersion compare
  • Qwen3.5 Plus 2026-02-15 vs Qwen3.8 Omni FlashSame lab
  • Qwen3.5 Plus 2026-02-15 vs Mistral Devstral Small 1.1New provider
  • GPT-5.1-Codex vs Dots3-Note PreviewNew provider
  • GPT-5.1-Codex vs Elephant AlphaNew provider
  • GPT-5.1-Codex vs ERNIE 4.5 300B A47BSame size

Model pages

  • GPT-5.1-Codex53 outputs, specs and price
  • Qwen3.5 Plus 2026-02-1553 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