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  5. GPT-5.5vsGrok 3
Updated Apr 2026

GPT-5.5vsGrok 3

GPT-5.5 has a larger context window than Grok 3 (1.1M tokens vs 128K tokens).

GPT-5.5 and Grok 3 compared across 52 shared prompts
SpecGPT-5.5Grok 3
Input price$5/M tokens—
Output price$30/M tokens—
Context window1.1M tokens128K tokens
WeightsClosed—
Free API (OpenRouter)NoNo
ReleasedApr 2026Feb 2025
Side by side

Same prompt, both answers

Opening lines from 6 of the 52 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…

GPT-5.5125 words
Smoky Sunset Chickpea Skillet 7 Pantry Ingredients 1 can chickpeas, undrained 1 can diced tomatoes 2 tablespoons olive oil 1 teaspoon garlic powder 1 teaspoon smoked paprika 1/2 teaspoon ground cumin 1/2 teaspoon salt Estimated Time Prep time: 5 minutes Cook time: 15 minutes Total time: 20 minutes Instructions Heat the…
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Grok 3245 words
Recipe: Cocoa Comet Mug Cake This simple, decadent chocolate mug cake is a quick treat that transforms basic pantry staples into a warm, fudgy delight. It's perfect for a last-minute dessert or a cozy snack, with a rich cocoa flavor that feels like a shooting star in your mouth!
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Mini LBO Underwrite

You are underwriting a 5-year LBO for a private equity investment committee. Company (fictional): HarborTech Services (HTS) –…

GPT-5.5563 words
Key assumptions Entry closes at end of FY2025; exit at end of FY2030. Interest is calculated on beginning-of-year debt balances. Term Loan amortization = 1.0% of original Term Loan principal = $4.8m/year. Mezz PIK = 2.0% of beginning-of-year Mezz balance, added to principal annually.
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Grok 3769 words
Let’s underwrite this 5-year LBO for HarborTech Services (HTS). I'll break this down step-by-step, keeping calculations clear and concise. Step 1: Sources & Uses at Entry (End of FY2025) EBITDA (FY2025): $120m Purchase Price: 12.0x EBITDA = 12.0 * $120m = $1,440m (Enterprise Value) Transaction Fees: 2.0% of EV = 0.02 *…
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Generate a Stand-Up Routine

Write a 3-minute stand-up comedy routine that isn't based on puns.

GPT-5.5605 words
So I’ve been trying to be healthier lately, which is just a polite way of saying I bought vegetables and watched them die slowly in my refrigerator. Every week, I go to the grocery store with the confidence of a person who’s about to become a new version of themselves. I’m like, “This week? Spinach. Salmon.
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Grok 3477 words
Alright, here’s a 3-minute stand-up comedy routine—no puns, just some observational absurdity and a bit of self-deprecation to keep it relatable. Hey, everybody! Good to be here. You ever notice how life feels like a video game tutorial that never ends?
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Character Voice Test

Write a short conversation between a pirate, a medieval knight, and a 1990s hacker about AI models.

GPT-5.5121 words
Pirate: Arrr, this AI model be like a treasure map—feed it enough scrolls, and it points ye toward answers. Knight: A curious enchantment indeed. Yet can it reason with honor, or merely mimic the bards who trained it? Hacker: Dude, it’s basically pattern recognition at massive scale.
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Grok 3454 words
Setting: A mystical tavern where time travelers and characters from different eras collide. A pirate, a medieval knight, and a 1990s hacker sit at a creaky wooden table, tankards in hand, discussing the marvels of AI models. Pirate (Captain Blackbeard): Arr, mateys!
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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.…

GPT-5.5519 words
Weak claim Why it’s weak How to strengthen it 1. “Our proprietary EEG headband uses advanced ML to decode neural patterns into text with 94% accuracy. Works with any language, any device.” This is the biggest technical red flag.
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Grok 3993 words
Below is my analysis of the three weakest claims in the MindMeld AI pitch deck summary. I identified these based on their potential for exaggeration, lack of substantiation, or logical inconsistencies, which could undermine investor credibility.
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Advanced Investment Memo (IC Memo)

You are writing an internal investment committee memo for a long/short equity fund. Company (fictional): LedgerLift (ticker: LLLT) – B2B…

GPT-5.51,055 words
LedgerLift (LLLT) IC Memo — Fictional Recommendation: Pass / Watchlist Current price: $46 Market cap: $8.7B; EV: $7.3B after $1.4B net cash 12-month fair value range: $40–$50/share Thesis, 2 sentences: LedgerLift is a high-quality mid-market spend management/AP automation SaaS asset with 92% subscription revenue, 123%…
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Grok 3883 words
Internal Investment Committee Memo Date: [Insert Date] Subject: LedgerLift (LLLT) – Recommendation and Analysis Prepared by: [Your Name] 1. Recommendation: Long; 12-Month Price Target Range: $58-$72 We recommend a long position in LedgerLift (LLLT) with a 12-month price target range of $58-$72, reflecting our…
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Our Verdict
GPT-5.5
GPT-5.5
Grok 3
Grok 3Runner-up

Not enough votes to call it. On the specs, GPT-5.5 has the edge: newer, bigger context window.

Too close to call

Reviewing agent-written code?See a Brief PR report

API pricing

Cost per 1M tokens

GPT-5.5
Input
$5.00
Output
$30.00
Grok 3
Input
—
Output
—
Where to run it

3 hosts, cheapest first

GPT-5.53 hosts
HostInOutContextUptime
Azure AI Foundry$5.00 in·$30.00 out·1.1M·99.9% upOpenAI$5.00 in·$30.00 out·1.1M·99.9% upAmazon Bedrock$5.50 in·$33.00 out·1.1M—
Grok 3

No hosts listed on OpenRouter.

Per million tokens. Prices and uptime via OpenRouter, checked 25 Sep 2026.

Writing DNA

Style Comparison

Similarity
46%

Grok 3 uses 2.5x more emoji

GPT-5.5
Grok 3
58%Vocabulary54%
18wSentence Length17w
0.74Hedging0.65
2.9Bold2.6
5.1Lists2.3
0.00Emoji0.02
1.68Headings0.48
0.03Transitions0.20
Based on 26 + 27 text responses
Research

What we learned reading every model

FAQ

Common questions

GPT-5.5 is developed by OpenAI while Grok 3 is developed by xAI. GPT-5.5 has a 1.1M token context window vs Grok 3's 128K. You can compare their actual outputs across 52 challenges on Rival to see how they differ in practice.

It depends on your use case. GPT-5.5 and Grok 3 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.

This page shows a side-by-side comparison of GPT-5.5 and Grok 3 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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