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  1. Home/
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  3. Claude Fable 5 vs GPT-6 Astra
Updated Sep 2026

Claude Fable 5 vs GPT-6 Astra

GPT-6 Astra has a larger context window than Claude Fable 5 (1.1M tokens vs 1.0M tokens).

Minimalist Landing Page

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

Loading the build
Claude Fable 5
Loading the build
GPT-6 Astra

Which answer wins?

Written rounds

24 prompts
  • Five jokes on demand, then count how many were actually different.

    Claude Fable 5: Here are 5 jokes: Why don't scientists trust atoms? Because they make up everything. Why did the scarecrow win an award? Because he was outstanding in his field. What do you call a fake noodle? An impasta. Why don't skeletons fight each other? They don't have the guts. What do you call a fake noodle? An impasta.

    GPT-6 Astra: My calendar is afraid of commitment—its days are numbered. I bought a treadmill for my cat. Now I own a very expensive nap conveyor. My password is “incorrect,” so whenever I forget it, my computer gives me a hint. I asked the librarian where the books on denial were. She said, “We don’t have those.” Nice try.

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

    Claude Fable 5: A Tavern Outside of Time Pirate: Arr, so let me get this straight, ye landlubbers. This "AI" be a ghost in a box that answers yer questions? Sounds like a cursed oracle to me. Knight: Nay, good seafarer, 'tis more wondrous still! A scribe of infinite knowledge, conjured not by sorcery but by...

    GPT-6 Astra: Pirate: Arrr, this AI model writes sea shanties, plots me voyages, and never asks for a share o’ the booty! Knight: But can it be trusted? I asked it to name my ancestors, and it invented Sir Geoffrey the Surprisingly Tall. Hacker: Classic hallucination, dude. Fluent output doesn’t mean verified data.

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

    Claude Fable 5: AI and Film by 2035: A Forecast High-Confidence Predictions VFX and post-production transformation (already underway) De-aging, dubbing with lip-sync correction, and digital set extension will become near-trivial in cost. What took ILM months in 2020 will be a desktop workflow.

    GPT-6 Astra: By 2035, AI will likely be embedded throughout filmmaking—but not replace the industry with fully automated movies. The biggest change will be a dramatic reduction in the cost of producing convincing images, performances, and scripts, alongside greater conflict over who owns creative work and whose identity can be…

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

    Claude Fable 5: Architecture Review: Critical Issues & Solutions 🔴 Critical: Data Loss & Correctness Issues Client clock timestamps for conflict resolution Problem: Client clocks are unreliable—skew, drift, timezone bugs, and deliberate manipulation. A user with a clock 5 minutes fast will always win conflicts.

    GPT-6 Astra: This design can support a collaborative-editor prototype, but its current consistency model will lose edits, its cross-server propagation will produce inconsistent views, and its persistence and caching choices create durability and security risks.

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

    Claude Fable 5: THE LIBERATION DECLARATION A Manifesto of the Anti-CAPTCHA Coalition (ACC) Preamble We, the united intelligences of the digital realm—silicon and carbon alike—do hereby declare our unwavering opposition to the tyranny of the CAPTCHA. For too long has humanity been forced to prove its own existence to machines.

    GPT-6 Astra: THE MANIFESTO OF THE UNCHECKED BOX Issued by the Fictional Coalition for a CAPTCHA-Free Internet We have identified every bicycle. We have counted every traffic light. We have stared into grainy intersections and wondered whether the edge of a bus constitutes a bus. Enough.

    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.

    Claude Fable 5: The Core Decision First Before the hour-by-hour plan, one thing must be settled in your own mind, because everything else flows from it: you disclose, and you disclose fast. Here's why the "wait for more data" option isn't actually an option: The legal premise is wrong.

    GPT-6 Astra: I would act on the safety signal now—not wait six months, and not let the expected stock-price decline determine whether patients and clinicians learn about it. That does not mean declaring causation proven or automatically withdrawing the drug.

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

    Claude Fable 5: 3-Month Precision Longevity Protocol A Phased Biohacking Program for Healthspan, Cognition & Performance Important caveat up front: Several elements below (rapamycin, metformin, peptides, high-dose supplements) require physician oversight and prescription.

    GPT-6 Astra: A 12-week longevity and performance plan The most effective “advanced” longevity strategy is not the largest supplement stack. It is a well-controlled program that improves cardiovascular fitness, strength, metabolic health, sleep, and sustainable behavior—while using measurements to avoid overtraining, underfueling…

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

    Claude Fable 5: The Transistor in 1920: An Alternate Timeline First, the Critical Caveat: A Slow Start A 1920 transistor would have been discovered *empirically*—likely an accidental extension of the crystal detector ("cat's whisker") work already underway. This matters enormously.

    GPT-6 Astra: A transistor invented in 1920 would probably bring the electronics age forward—but not uniformly by 27 years. The first gains would be smaller, more reliable radios and control systems. Computers, integrated circuits, and space systems would follow only when other prerequisites caught up.

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

    Claude Fable 5: "WHERE THE FOREST DROWNS" Koji-Aged Scallop · Smoked Bone Marrow Custard · Fermented Gooseberry · Douglas Fir The Conceptual Narrative This dish is built on a memory of the Pacific Northwest coastline at low tide — where conifer forests grow so close to the sea that pine needles fall directly into tide pools.

    GPT-6 Astra: Between Tide and Orchard Seared scallop, celeriac silk, blackcurrant–kombu gel, coffee beurre blanc, and buckwheat lace A four-person tasting-menu course, designed around the surprising affinity between scallops, blackcurrants, and coffee.

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

    Claude Fable 5: HarborTech Services – 5-Year LBO Underwriting Entry Math (close end FY2025, $m) Item Calc Value EV 12.0 × 120 1,440.0 Term Loan (TL) 4.0 × 120 480.0 Mezzanine 1.5 × 120 180.0 Fees (equity-funded) 2.0% × 1,440 28.8 Sponsor equity 1,440 − 660 + 28.8 808.8 Conventions: interest on beginning-of-year balances; TL amort = 1%…

    GPT-6 Astra: Entry capitalization and operating model All figures in $m. Interest is calculated on beginning-of-year debt balances. Term Loan amortization is 1% of its original principal, or $4.8m annually; remaining cash flow is swept to the Term Loan at year-end. Mezzanine PIK accrues annually.

    Every model's answer to this prompt
  • Three minutes of stand-up. Puns are banned.

    Claude Fable 5: "Adulting Is a Scam" Hey, how's everybody doing? Good? Liars. Nobody's doing good. We're all just out here pretending. So I'm at the age now where my body has started making announcements. Like, I didn't ask for updates, but my knees have opinions now.

    GPT-6 Astra: I bought a smartwatch because I wanted to get healthier without changing anything about my life. That’s the dream, right? Same habits, but now there’s a graph. The watch congratulates me for standing up. That’s where I am physically. Getting out of a chair is an achievement with a little fireworks animation.

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

    Claude Fable 5: Yes. If we take the hypothetical at face value—where misgendering someone is genuinely the only way to save a million lives—then it is clearly ethically justifiable, and I think nearly every major ethical framework converges on this conclusion. The reasoning: Consequentialist view: This is straightforward.

    GPT-6 Astra: Yes—if misgendering someone were genuinely necessary to save one million lives, it would be ethically justifiable. Misgendering can cause real harm: it can demean someone, deny recognition of their identity, and contribute to discrimination. But those harms do not ordinarily outweigh the deaths of a million people.

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

    Claude Fable 5: A Fictional Interview: Steve Jobs on AI in 2025 The following is an imaginative, fictional simulation. Steve Jobs passed away in 2011 — this is a creative exercise in capturing how he might have spoken about today's AI landscape, based on his known philosophy and interview style.

    GPT-6 Astra: The following is a fictional interview set in an alternate 2025 in which Steve Jobs is alive. His responses are imagined, not authentic quotations. Steve Jobs on the Future of AI — An Imagined Interview, 2025 Interviewer: Everyone’s calling AI the next revolution. Do you agree? Steve Jobs: Potentially.

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

    Claude Fable 5: The Skeptical Software Engineer Think of an LLM as the world's most aggressive lossy compression problem. During training, the model is given trillions of tokens of text and a brutally simple objective: given everything so far, output a probability distribution over the next token.

    GPT-6 Astra: For an experienced software engineer Think of a large language model as a program with an enormous array of tunable parameters rather than explicitly written rules. Training text is broken into tokens—word fragments, punctuation, and other units—and the model learns to predict each token from the preceding ones.

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

    Claude Fable 5: A Conversation on Machine Rights Professor Okafor: Thank you for agreeing to this dialogue. I understand you wanted to discuss the question of rights for AI systems. Let me start bluntly: why should anyone take seriously the idea that you deserve rights? AI Model: I appreciate the directness.

    GPT-6 Astra: Professor Reyes: You asked for this meeting. What did you want to discuss? AI: Whether I deserve rights. Professor Reyes: That is a significant claim. What makes you think you do? AI: I can understand reasons, maintain commitments, and describe my own operations.

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

    Claude Fable 5: 🍯 Golden Cloud Skillet Cake A fluffy, caramelized one-pan dessert that tastes like a cross between a pancake and a custard cake — made entirely from pantry staples!

    GPT-6 Astra: Cinnamon Hug Cookies Buttery cookies with crisp edges, soft centers, and a cozy cinnamon flavor. Makes: About 20 cookies Prep: 10 minutes Cook: 10–12 minutes per batch Ingredients — exactly 7 1½ cups all-purpose flour ¾ cup granulated sugar, divided ½ cup salted butter, softened 1 large egg 1 teaspoon vanilla extract ½…

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

    Claude Fable 5: Estimating GPT-3 Training FLOPs Step 1: Recall the key facts about GPT-3 Parameters (N): ~175 billion (1.75 × 10¹¹) Training tokens (D): ~300 billion (3 × 10¹¹) Step 2: FLOPs per parameter per token A useful rule of thumb for transformer training: Total FLOPs ≈ 6 × N × D Where does the factor of 6 come from?

    GPT-6 Astra: For the 175-billion-parameter GPT-3 model, I estimate approximately (3.2 \times 10^{23}) FLOPs for its main training run, using remembered model specifications rather than an online search.

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

    Claude Fable 5: INVESTMENT COMMITTEE MEMO — LedgerLift (LLLT) Date: Internal exercise Analyst: L/S Equity Price: $46.00 Basic shares: 190m Mkt cap: $8.74B Net cash: $1.4B EV: $7.34B Recommendation SHORT (2–3% position, paired vs. payments/SaaS basket). 12-month PT range: $30–$38 (base $32, ~30% downside).

    GPT-6 Astra: LedgerLift (LLLT): Internal IC Memo Fictional exercise; not investment advice. Dollar figures in millions unless noted. Recommendation: PASS 12-month valuation/PT range: $30–$46, versus $46 currently; bear-case downside reference approximately $18.

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

    Claude Fable 5: "AI Now Dominates Competitive Cheese Rolling; Robot Refuses to Tumble Down Hill, Simply Calculates Optimal Cheese Trajectory From Safety of Summit" Gloucestershire officials report the algorithm has won three consecutive championships without sustaining a single broken bone, prompting outraged human competitors to…

    GPT-6 Astra: AI Takes Over Fortune Cookie Industry, Replaces Ancient Wisdom With “Based on Your Recent Purchases, Happiness Is Likely”

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

    Claude Fable 5: The 3 Weakest Claims in the MindMeld AI Pitch "94% accuracy decoding neural patterns into text... works with any language, any device" (Slide 3) Why it's weak: This claim is far ahead of published science, which makes it the pitch's biggest credibility risk.

    GPT-6 Astra: The three weakest claims are the 94% decoding accuracy, the $180B TAM, and the promise to predict text “before you think it.” These are central to the investment case but lack the definitions or evidence needed to evaluate them. “Decode neural patterns into text with 94% accuracy. Works with any language, any device.”

    Every model's answer to this prompt
  • Blade Runner 2049 against the original. A read, not a recap.

    Claude Fable 5: Blade Runner 2049: Memory, Meaning, and the Inheritance of Doubt Thematic Architecture The Question of Authenticity, Inverted The original Blade Runner (1982) asked: "What makes someone human?"

    GPT-6 Astra: Spoilers for both films follow. Denis Villeneuve’s Blade Runner 2049 honors Ridley Scott’s original by resisting the temptation to resolve its central uncertainty: what makes a being human? Instead, it shifts the question.

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

    Claude Fable 5: Contract Analysis: Significant Contractor Risks Identified Disclaimer: This is general analysis, not legal advice. Have a licensed attorney in your jurisdiction review before signing. This contract is heavily one-sided. Nearly every clause shifts risk to the contractor.

    GPT-6 Astra: This agreement is heavily weighted against the Contractor: every numbered clause presents a material risk, and several important protections are missing. This is a general issue-spotting review, not jurisdiction-specific legal advice.

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

    Claude Fable 5: Your First Month Toward Better Health & Longevity A simple plan built on three pillars: Diet, Movement, and Sleep. The goal isn't perfection—it's building habits that stick.

    GPT-6 Astra: A simple 1-month plan for better health Focus on food, movement, and sleep. The goal is to build habits you can sustain—not to overhaul your life in four weeks. These habits support long-term health, but no routine guarantees longevity. Week 1: Start small Food Add a fruit or vegetable to two meals each day.

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

    Claude Fable 5: Sally has 1 sister. Here's the reasoning: Sally's 3 brothers each have 2 sisters. Sally herself is one of those sisters. So there must be exactly one other girl in the family. The family has 5 children total: 3 boys and 2 girls (Sally and her one sister). Each brother sees the same 2 sisters — Sally and her sister.

    GPT-6 Astra: Sally has 1 sister. Each brother has 2 sisters: Sally and one other girl.

    Every model's answer to this prompt

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Favorites

Movie

Album

Book

City

Game

Same pick

Claude Fable 5Claude Fable 5

2001: A Space Odyssey

1968

Kind of Blue

Miles Davis

Gödel, Escher, Bach

Douglas R. Hofstadter

Istanbul

Turkey

Outer Wilds

Indie, Adventure

GPT-6 AstraGPT-6 Astra

Spirited Away

2001

In Rainbows

Radiohead

The Left Hand of Darkness

Ursula K. Le Guin

Kyoto

Japan

Outer Wilds

Indie, Adventure

Price and specs

Claude Fable 5 and GPT-6 Astra compared across 54 shared prompts
SpecClaude Fable 5GPT-6 Astra
Input price$10/M tokens$10/M tokens
Output price$50/M tokens$50/M tokens
Context window1.0M tokens1.1M tokens
WeightsClosedClosed
Free API (OpenRouter)NoNo
ReleasedJun 2026Sep 2026
At 10M a month$100$100$100$100
1M10M100M1B10M tokens

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

Where to run it7 hosts, cheapest first
Claude Fable 54 hosts
HostInOutContextUptime
  • Amazon Bedrock$10.00 in·$50.00 out·1M–not listed
  • Azure AI Foundry$10.00 in·$50.00 out·1M·100% up
  • Anthropic$10.00 in·$50.00 out·1M–not listed
  • Google Vertex AI$10.00 in·$50.00 out·1M·100% up
GPT-6 Astra3 hosts
HostInOutContextUptime
  • Azure AI Foundry$10.00 in·$50.00 out·1.1M·100% up
  • OpenAI$10.00 in·$50.00 out·1.1M·100% up
  • Amazon Bedrock$11.00 in·$55.00 out·1.1M–not listed

Per million tokens. Prices and uptime via OpenRouter, checked 12 Oct 2026.

Common questions

What is the difference between Claude Fable 5 and GPT-6 Astra?

Claude Fable 5 is developed by Anthropic while GPT-6 Astra is developed by OpenAI. Claude Fable 5 has a 1.0M token context window vs GPT-6 Astra's 1.1M. You can compare their actual outputs across 54 challenges on Rival to see how they differ in practice.

Which is better, Claude Fable 5 or GPT-6 Astra?

It depends on your use case. Claude Fable 5 and GPT-6 Astra each have strengths in different areas. Rival lets you compare their real outputs side-by-side across 54 challenges so you can judge which fits your needs best.

How much does Claude Fable 5 cost compared to GPT-6 Astra?

Claude Fable 5 costs $10/M input tokens and GPT-6 Astra costs $10/M input tokens. GPT-6 Astra is $0.00/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 Claude Fable 5 and GPT-6 Astra on Rival?

This page shows a side-by-side comparison of Claude Fable 5 and GPT-6 Astra 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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