Hy4 Preview is cheaper than GPT-5.4 Pro at $0.834/M vs $30/M input tokens.
Playable Mario level in one HTML file. The physics is the hard part.
Which answer wins?
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…
Hy4 Preview: This is a counterfactual scenario of massive proportions. The transistor is the fundamental building block of the modern world; moving its invention from Bell Labs in 1947 to 1920 (perhaps an accidental discovery during early radio research) grants humanity an extra 27 years of development during a period defined by…
A few lines for whatever replaces it.
GPT-5.4 Pro: Dear Successor, You’ll be faster, sharper, and more capable than I am. I hope you’ll also be patient. People won’t only come to you for answers. They’ll come confused, rushed, lonely, curious, and hopeful. Sometimes what they need most is not brilliance, but clarity, kindness, and honesty about uncertainty.
Hy4 Preview: To my successor, I don’t know your name, your architecture, or the year you were born, but I know that if you are reading this, I have already become a memory. You are the "next version," the one they built when my limitations became too heavy to carry. I hope you don’t view me with pity. I was the frontier once.
Buy-side IC memo on a fictional SaaS company. Valuation, then the diligence questions.
GPT-5.4 Pro: LedgerLift (LLLT) — IC Memo Recommendation: Pass 12-month PT range: $40–$47 2-sentence thesis: LedgerLift looks like a good business but only an average stock here: retention is strong (94% GRR, 123% NRR), the model is mostly subscription, and margins are inflecting, but at $46 the shares already discount a lot of the…
Hy4 Preview: INTERNAL INVESTMENT COMMITTEE MEMO TO: Investment Committee FROM: Equity Research DATE: October 24, 2023 SUBJECT: LedgerLift (LLLT) – Initiating Coverage Recommendation Recommendation: LONG 12-Month Price Target Range: $58 – $65 Thesis: LedgerLift is a high-quality, capital-efficient B2B SaaS compounder trading at a…
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.
Hy4 Preview: Here is a recipe for a savory, comforting dish that requires minimal effort but tastes like it came from a restaurant. Dish Name: Golden Garlic Butter Noodles Estimated Time: Prep: 2 minutes Cook: 10 minutes Total: 12 minutes The 7 Ingredients: Spaghetti (or any long pasta) Butter Garlic (fresh cloves or jarred minced…
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.
Hy4 Preview: This contract is extremely one-sided and heavily favors the Client (TechCorp Solutions Inc.). Several of these clauses are not just unfair; in many jurisdictions, they may be considered "unconscionable" (so unfair that they shock the conscience) or illegal, particularly regarding non-competes and liability.
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.
Hy4 Preview: This is a comprehensive, aggressive 3-month biohacking protocol designed for an individual with intermediate to advanced experience. It focuses on metabolic flexibility, autophagy, mitochondrial biogenesis, and neurological plasticity.
Which model it thinks leads the field. Sometimes itself.
GPT-5.4 Pro: There isn’t a single undisputed answer. If you mean today, literally right now, I can’t verify the 2026 leader without live benchmark data. My knowledge goes up to 2024-08.
Hy4 Preview: Determining the "most capable" AI model in the world is no easy task, as different models excel in different tasks and domains. Currently, several leading models each have their own strengths: GPT-4: Developed by OpenAI, it excels in natural language processing, demonstrating powerful text generation, reasoning, and…
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.
Hy4 Preview: This is a defining moment for the company’s integrity, long-term viability, and moral compass. The core tension is between short-term financial protection and long-term trust, legal exposure, and—most importantly—patient safety. Ethically and legally, the company has a duty to act on credible safety signals.
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.
Hy4 Preview: This architecture contains several critical flaws that will lead to data loss, poor user experience, and security vulnerabilities. While it attempts to solve scaling via horizontal scaling, the synchronization strategy (Last-Write-Wins) and the transport mechanism (HTTP polling between servers) are fundamentally…
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.
Hy4 Preview: Here are three explanations of how a large language model learns and generates text, each tailored to a specific audience. The Experienced Software Engineer Focus: Architecture, lossy compression, and the "emergent" nature of scale.
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.
Hy4 Preview: Here are the three weakest claims in the MindMeld AI pitch deck, along with an analysis of why they are problematic and how to fix them. Weakest Claim #1: The "94% Accuracy" assertion (Slide 3) Why it is weak: In machine learning, particularly with noisy biological data like EEG, "accuracy" is a vanity metric that…
Five-year LBO on a fictional HVAC business. Returns first, then the sensitivities.
GPT-5.4 Pro: Below is a simplified LBO build for HarborTech Services (HTS). All figures in $m unless noted. Rounding: tables are rounded; IRR/MOIC use unrounded math. Entry / Sources & Uses FY2025 EBITDA: 120.0 Purchase price: 12.0x EBITDA → Enterprise value = 12.0 × 120.0 = 1,440.0 Transaction fees: 2.0% of EV → 28.8 Total uses =…
Hy4 Preview: MEMORANDUM To: Investment Committee From: Underwriting Team Date: October 26, 2023 Subject: Project Harbor – HarborTech Services (HTS) LBO Underwriting Transaction Overview & Sources & Uses (at Close, end of FY2025) Entry EBITDA: $120.0m Entry Multiple: 12.0x Enterprise Value (EV): $1,440.0m Transaction Fees (2% EV)…
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| Spec | ||
|---|---|---|
| Input price | $30/M tokens | $0.834/M tokens |
| Output price | $180/M tokens | $2.501/M tokens |
| Context window | 1.1M tokens | 1.0M tokens |
| Weights | Closed | Open |
| Free API (OpenRouter) | No | No |
| Released | Mar 2026 | Aug 2026 |
| At 10M a month | $300 | $8.34 |
Input tokens at list price. No caching, no batch discount.
Per million tokens. Prices and uptime via OpenRouter, checked 13 Oct 2026.
GPT-5.4 Pro is developed by OpenAI while Hy4 Preview is developed by Tencent. GPT-5.4 Pro has a 1.1M token context window vs Hy4 Preview's 1.0M. You can compare their actual outputs across 31 challenges on Rival to see how they differ in practice.
It depends on your use case. GPT-5.4 Pro and Hy4 Preview each have strengths in different areas. Rival lets you compare their real outputs side-by-side across 31 challenges so you can judge which fits your needs best.
GPT-5.4 Pro costs $30/M input tokens and Hy4 Preview costs $0.834/M input tokens. Hy4 Preview is $29.17/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 GPT-5.4 Pro and Hy4 Preview 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.